147-460: An abacus ( pl. : abaci or abacuses ), also called a counting frame , is a hand -operated calculating tool which was used from ancient times in the ancient Near East , Europe, China, and Russia, until the adoption of the Hindu–Arabic numeral system . An abacus consists of a two-dimensional array of slidable beads (or similar objects). In their earliest designs, the beads could be loose on
294-405: A writing implement and paper (needed for algorism ) or an electric power source . Merchants, traders, and clerks in some parts of Eastern Europe , Russia, China, and Africa use abacuses. The abacus remains in common use as a scoring system in non- electronic table games. Others may use an abacus due to visual impairment that prevents the use of a calculator. The abacus is still used to teach
441-540: A "Sumerian renaissance" in the past. Already, the region was becoming more Semitic than Sumerian, with the resurgence of the Akkadian-speaking Semites in Assyria and elsewhere, and the influx of waves of Semitic Martu ( Amorites ), who founded several competing local powers in the south, including Isin , Larsa , Eshnunna and later, Babylonia. The last of these eventually came to briefly dominate
588-543: A 5-digit base-20 system. The word Nepōhualtzintzin Nahuatl pronunciation: [nepoːwaɬˈt͡sint͡sin] comes from Nahuatl , formed by the roots; Ne – personal -; pōhual or pōhualli Nahuatl pronunciation: [ˈpoːwalːi] – the account -; and tzintzin Nahuatl pronunciation: [ˈt͡sint͡sin] – small similar elements. Its complete meaning was taken as: counting with small similar elements. Its use
735-486: A bead frame similar to the Russian abacus but with straight wires and a vertical frame is common (see image). The wireframe may be used either with positional notation like other abacuses (thus the 10-wire version may represent numbers up to 9,999,999,999), or each bead may represent one unit (e.g. 74 can be represented by shifting all beads on 7 wires and 4 beads on the 8th wire, so numbers up to 100 may be represented). In
882-591: A calculation as quickly as with a physical instrument. The Chinese abacus migrated from China to Korea around 1400 AD. Koreans call it jupan (주판), supan (수판) or jusan (주산). The four-beads abacus (1:4) was introduced during the Goryeo Dynasty . The 5:1 abacus was introduced to Korea from China during the Ming Dynasty. Some sources mention the use of an abacus called a nepohualtzintzin in ancient Aztec culture. This Mesoamerican abacus used
1029-651: A century in the Third Dynasty of Ur at approximately 2100–2000 BC, but the Akkadian language also remained in use for some time. The Sumerians were entirely unknown during the early period of modern archeology. Jules Oppert was the first scholar to publish the word Sumer in a lecture on 17 January 1869. The first major excavations of Sumerian cities were in 1877 at Girsu by the French archeologist Ernest de Sarzec , in 1889 at Nippur by John Punnett Peters from
1176-410: A compact fist, presumably for fighting purposes. The fist is compact and thus effective as a weapon. It also provides protection for the fingers. However, this is not widely accepted to be one of the primary selective pressures acting on hand morphology throughout human evolution, with tool use and production being thought to be far more influential. Sumer Sumer ( / ˈ s uː m ər / )
1323-589: A cross where they intersect with the vertical line. Also from this time frame, the Darius Vase was unearthed in 1851. It was covered with pictures, including a "treasurer" holding a wax tablet in one hand while manipulating counters on a table with the other. The normal method of calculation in ancient Rome, as in Greece, was by moving counters on a smooth table. Originally pebbles ( Latin : calculi ) were used. Marked lines indicated units, fives, tens, etc. as in
1470-598: A difficult environment. Others have suggested a continuity of Sumerians, from the indigenous hunter-fisherfolk traditions, associated with the bifacial assemblages found on the Arabian littoral. Juris Zarins believes the Sumerians may have been the people living in the Persian Gulf region before it flooded at the end of the last Ice Age. In the early Sumerian period, the primitive pictograms suggest that There
1617-578: A diversity of forms and materials in other cultures. Sanchez wrote in Arithmetic in Maya that another base 5, base 4 abacus had been found in the Yucatán Peninsula that also computed calendar data. This was a finger abacus, on one hand, 0, 1, 2, 3, and 4 were used; and on the other hand 0, 1, 2, and 3 were used. Note the use of zero at the beginning and end of the two cycles. The quipu of
SECTION 10
#17327972165681764-416: A flat surface or sliding in grooves. Later the beads were made to slide on rods and built into a frame, allowing faster manipulation. Each rod typically represents one digit of a multi-digit number laid out using a positional numeral system such as base ten (though some cultures used different numerical bases ). Roman and East Asian abacuses use a system resembling bi-quinary coded decimal , with
1911-399: A higher degree, the hands of other primates are anatomically similar and the dexterity of the human hand can not be explained solely on anatomical factors. The neural machinery underlying hand movements is a major contributing factor; primates have evolved direct connections between neurons in cortical motor areas and spinal motoneurons , giving the cerebral cortex monosynaptic control over
2058-455: A number, then are manipulated to perform a mathematical operation with another number, and their final position can be read as the result (or can be used as the starting number for subsequent operations). In the ancient world, abacuses were a practical calculating tool. Although calculators and computers are commonly used today instead of abacuses, abacuses remain in everyday use in some countries. The abacus has an advantage of not requiring
2205-523: A pencil—reflects individual brain functioning. Among humans, the hands play an important function in body language and sign language . Likewise, the ten digits of two hands and the twelve phalanges of four fingers (touchable by the thumb) have given rise to number systems and calculation techniques. Many mammals and other animals have grasping appendages similar in form to a hand such as paws , claws , and talons, but these are not scientifically considered to be grasping hands. The scientific use of
2352-399: A primitive trait, while the palms of other extant higher primates are elongated to the extent that some of the thumb's original function has been lost (most notably in highly arboreal primates such as the spider monkey ). In humans, the big toe is thus more derived than the thumb. There is a hypothesis suggesting the form of the modern human hand is especially conducive to the formation of
2499-518: A representation of the abacus. It is the belief of Old Babylonian scholars, such as Ettore Carruccio, that Old Babylonians "seem to have used the abacus for the operations of addition and subtraction; however, this primitive device proved difficult to use for more complex calculations". Greek historian Herodotus mentioned the abacus in Ancient Egypt . He wrote that the Egyptians manipulated
2646-535: A season of the year lasts, two Nepōhualtzitzin (182) is the number of days of the corn's cycle, from its sowing to its harvest, three Nepōhualtzintzin (273) is the number of days of a baby's gestation, and four Nepōhualtzintzin (364) completed a cycle and approximated one year. When translated into modern computer arithmetic, the Nepōhualtzintzin amounted to the rank from 10 to 18 in floating point , which precisely calculated large and small amounts, although round off
2793-407: A single slanted deck, with ten beads on each wire (except one wire with four beads for quarter- ruble fractions). 4-bead wire was introduced for quarter- kopeks , which were minted until 1916. The Russian abacus is used vertically, with each wire running horizontally. The wires are usually bowed upward in the center, to keep the beads pinned to either side. It is cleared when all the beads are moved to
2940-505: A switch on the computer in either an "on" or "off" position. An adapted abacus, invented by Tim Cranmer, and called a Cranmer abacus is commonly used by visually impaired users. A piece of soft fabric or rubber is placed behind the beads, keeping them in place while the users manipulate them. The device is then used to perform the mathematical functions of multiplication, division, addition, subtraction, square root, and cube root. Although blind students have benefited from talking calculators,
3087-635: A top deck (containing one or two beads) representing fives and a bottom deck (containing four or five beads) representing ones. Natural numbers are normally used, but some allow simple fractional components (e.g. 1 ⁄ 2 , 1 ⁄ 4 , and 1 ⁄ 12 in Roman abacus ), and a decimal point can be imagined for fixed-point arithmetic . Any particular abacus design supports multiple methods to perform calculations, including addition , subtraction , multiplication , division , and square and cube roots . The beads are first arranged to represent
SECTION 20
#17327972165683234-427: A transitional element to the fifth metacarpal. Together with the thumb, the four fingers form four oblique arches, of which the arch of the index finger functionally is the most important, especially for precision grip, while the arch of the little finger contribute an important locking mechanism for power grip. The thumb is undoubtedly the "master digit" of the hand, giving value to all the other fingers. Together with
3381-470: A useful tool throughout life. Hand A hand is a prehensile , multi- fingered appendage located at the end of the forearm or forelimb of primates such as humans , chimpanzees , monkeys , and lemurs . A few other vertebrates such as the koala (which has two opposable thumbs on each "hand" and fingerprints extremely similar to human fingerprints ) are often described as having "hands" instead of paws on their front limbs. The raccoon
3528-436: A vertical line, capped with a semicircle at the intersection of the bottom-most horizontal line and the single vertical line. Below these lines is a wide space with a horizontal crack dividing it. Below this crack is another group of eleven parallel lines, again divided into two sections by a line perpendicular to them, but with the semicircle at the top of the intersection; the third, sixth and ninth of these lines are marked with
3675-405: Is a one while placing the wick on the number hundred means it is called a hundred, and on the number one thousand means it is a thousand". It is unclear exactly what this arrangement may have been. Around the 5th century, Indian clerks were already finding new ways of recording the contents of the abacus. Hindu texts used the term śūnya (zero) to indicate the empty column on the abacus. In Japan,
3822-587: Is considerable evidence concerning Sumerian music . Lyres and flutes were played, among the best-known examples being the Lyres of Ur . Sumerian culture was male-dominated and stratified. The Code of Ur-Nammu , the oldest such codification yet discovered, dating to the Ur III, reveals a glimpse at societal structure in late Sumerian law. Beneath the lu-gal ("great man" or king), all members of society belonged to one of two basic strata: The " lu " or free person, and
3969-569: Is first attested in proper names of the kings of Kish c. 2800 BC , preserved in later king lists. There are texts written entirely in Old Akkadian dating from c. 2500 BC . Use of Old Akkadian was at its peak during the rule of Sargon the Great ( c. 2334 –2279 BC), but even then most administrative tablets continued to be written in Sumerian, the language used by
4116-407: Is little break in historical continuity between the pre- and post-Sargon periods, and that too much emphasis has been placed on the perception of a "Semitic vs. Sumerian" conflict. It is certain that Akkadian was also briefly imposed on neighboring parts of Elam that were previously conquered, by Sargon. c. 2193–2119 BC (middle chronology) c. 2200 –2110 BC (middle chronology) Following
4263-474: Is located on one of the sides, parallel to the arm. A reliable way of identifying human hands is from the presence of opposable thumbs. Opposable thumbs are identified by the ability to be brought opposite to the fingers, a muscle action known as opposition. The skeleton of the human hand consists of 27 bones: the eight short carpal bones of the wrist are organized into a proximal row ( scaphoid , lunate , triquetral and pisiform ) which articulates with
4410-526: Is marked by a distinctive style of fine quality painted pottery which spread throughout Mesopotamia and the Persian Gulf . The oldest evidence for occupation comes from Tell el-'Oueili , but, given that environmental conditions in southern Mesopotamia were favourable to human occupation well before the Ubaid period, it is likely that older sites exist but have not yet been found. It appears that this culture
4557-404: Is most clearly seen at Tell el-'Oueili near Larsa , excavated by the French in the 1980s, where eight levels yielded pre-Ubaid pottery resembling Samarran ware. According to this theory, farming peoples spread down into southern Mesopotamia because they had developed a temple-centered social organization for mobilizing labor and technology for water control, enabling them to survive and prosper in
Abacus - Misplaced Pages Continue
4704-578: Is next to the four beads, and pressing the "clearing" button puts the upper bead in the upper position, and the lower bead in the lower position. The abacus is still manufactured in Japan, despite the proliferation, practicality, and affordability of pocket electronic calculators . The use of the soroban is still taught in Japanese primary schools as part of mathematics , primarily as an aid to faster mental calculation. Using visual imagery, one can complete
4851-476: Is often used, either on a string of beads or on a rigid framework. Physicist Richard Feynman was noted for facility in mathematical calculations. He wrote about an encounter in Brazil with a Japanese abacus expert, who challenged him to speed contests between Feynman's pen and paper, and the abacus. The abacus was much faster for addition, somewhat faster for multiplication, but Feynman was faster at division. When
4998-408: Is supplemented by the precision grip between the thumb and the distal finger pads made possible by the opposable thumbs. Hominidae (great apes including humans) acquired an erect bipedal posture about 3.6 million years ago , which freed the hands from the task of locomotion and paved the way for the precision and range of motion in human hands. Functional analyses of the features unique to
5145-663: Is the earliest known civilization , located in the historical region of southern Mesopotamia (now south-central Iraq ), emerging during the Chalcolithic and early Bronze Ages between the sixth and fifth millennium BC. Like nearby Elam , it is one of the cradles of civilization , along with Egypt , the Indus Valley , the Erligang culture of the Yellow River valley, Caral-Supe , and Mesoamerica . Living along
5292-497: Is to the neck of a metacarpal. One can also have a broken finger . The prehensile hands and feet of primates evolved from the mobile hands of semi- arboreal tree shrews that lived about 60 million years ago . This development has been accompanied by important changes in the brain and the relocation of the eyes to the front of the face, together allowing the muscle control and stereoscopic vision necessary for controlled grasping. This grasping, also known as power grip,
5439-505: Is usually described as having "hands" though opposable thumbs are lacking. Some evolutionary anatomists use the term hand to refer to the appendage of digits on the forelimb more generally—for example, in the context of whether the three digits of the bird hand involved the same homologous loss of two digits as in the dinosaur hand. The human hand usually has five digits: four fingers plus one thumb ; these are often referred to collectively as five fingers , however, whereby
5586-532: The Akkadian name for the "Sumerians", the ancient non- Semitic -speaking inhabitants of southern Mesopotamia . In their inscriptions, the Sumerians called their land "Kengir", the "Country of the noble lords" ( Sumerian : 𒆠 𒂗 𒄀 , romanized: ki-en-gi(-r) , lit. ''country" + "lords" + "noble''), and their language "Emegir" ( Sumerian : 𒅴𒂠 , romanized: eme-g̃ir or 𒅴𒄀 eme-gi 15 ). The origin of
5733-533: The French Revolution . The Salamis Tablet , found on the Greek island Salamis in 1846 AD, dates to 300 BC, making it the oldest counting board discovered so far. It is a slab of white marble 149 cm (59 in) in length, 75 cm (30 in) wide, and 4.5 cm (2 in) thick, on which are 5 groups of markings. In the tablet's center is a set of 5 parallel lines equally divided by
5880-472: The Incas was a system of colored knotted cords used to record numerical data, like advanced tally sticks – but not used to perform calculations. Calculations were carried out using a yupana ( Quechua for "counting tool"; see figure) which was still in use after the conquest of Peru. The working principle of a yupana is unknown, but in 2001 Italian mathematician De Pasquale proposed an explanation. By comparing
6027-585: The Middle East and were responsible for the spread of farming in the Middle East. However, contrary evidence strongly suggests that the first farming originated in the Fertile Crescent . Although not specifically discussing Sumerians, Lazaridis et al. 2016 have suggested a partial North African origin for some pre-Semitic cultures of the Middle East, particularly Natufians , after testing
Abacus - Misplaced Pages Continue
6174-416: The Middle East would have provided direct contact with India, allowing them to acquire the concept of zero and the decimal point from Indian merchants and mathematicians. The Abhidharmakośabhāṣya of Vasubandhu (316–396), a Sanskrit work on Buddhist philosophy , says that the second-century CE philosopher Vasumitra said that "placing a wick (Sanskrit vartikā ) on the number one ( ekāṅka ) means it
6321-523: The Muromachi era . It adopts the form of the upper deck one bead and the bottom four beads. The top bead on the upper deck was equal to five and the bottom one is similar to the Chinese or Korean abacus, and the decimal number can be expressed, so the abacus is designed as a 1:4 device. The beads are always in the shape of a diamond. The quotient division is generally used instead of the division method; at
6468-648: The Roman Empire and China. However, no direct connection has been demonstrated, and the similarity of the abacuses may be coincidental, both ultimately arising from counting with five fingers per hand. Where the Roman model (like most modern Korean and Japanese ) has 4 plus 1 bead per decimal place, the standard suanpan has 5 plus 2. Incidentally, this allows use with a hexadecimal numeral system (or any base up to 18) which may have been used for traditional Chinese measures of weight. (Instead of running on wires as in
6615-538: The Roman numeral system. Writing in the 1st century BC, Horace refers to the wax abacus, a board covered with a thin layer of black wax on which columns and figures were inscribed using a stylus. One example of archaeological evidence of the Roman abacus , shown nearby in reconstruction, dates to the 1st century AD. It has eight long grooves containing up to five beads in each and eight shorter grooves having either one or no beads in each. The groove marked I indicates units, X tens, and so on up to millions. The beads in
6762-649: The Soviet Union . The Russian abacus began to lose popularity only after the mass production of domestic microcalculators in 1974. The Russian abacus was brought to France around 1820 by mathematician Jean-Victor Poncelet , who had served in Napoleon 's army and had been a prisoner of war in Russia. The abacus had fallen out of use in western Europe in the 16th century with the rise of decimal notation and algorismic methods. To Poncelet's French contemporaries, it
6909-531: The University of Pennsylvania between 1889 and 1900, and in Shuruppak by German archeologist Robert Koldewey in 1902–1903. Major publications of these finds were " Decouvertes en Chaldée par Ernest de Sarzec " by Léon Heuzey in 1884, " Les Inscriptions de Sumer et d'Akkad " by François Thureau-Dangin in 1905, and " Grundzüge der sumerischen Grammatik " on Sumerian grammar by Arno Poebel in 1923. In
7056-558: The archaeological record shows clear uninterrupted cultural continuity from the time of the early Ubaid period (5300–4700 BC C-14 ) settlements in southern Mesopotamia. The Sumerian people who settled here, farmed the lands in this region that were made fertile by silt deposited by the Tigris and the Euphrates . Some archaeologists have speculated that the original speakers of ancient Sumerian may have been farmers, who moved down from
7203-473: The carpal tunnel and contribute to the deep and superficial palmar arches . Several muscle tendons attaching to the TCL and the distal carpals also contribute to maintaining the carpal arch. Compared to the carpal arches, the arch formed by the distal ends of the metacarpal bones is flexible due to the mobility of the peripheral metacarpals (thumb and little finger). As these two metacarpals approach each other,
7350-600: The chimpanzee–human last common ancestor (CHLCA) and absent in modern humans are still present in the hands of Australopithecus , Paranthropus , and Homo floresiensis . This suggests that the derived changes in modern humans and Neanderthals did not evolve until 2.5 to 1.5 million years ago or after the appearance of the earliest Acheulian stone tools, and that these changes are associated with tool-related tasks beyond those observed in other hominins. The thumbs of Ardipithecus ramidus , an early hominin, are almost as robust as in humans, so this may be
7497-419: The dermis of palmoplantar skin inhibit melanin production and thus the ability to tan , and promote the thickening of the stratum lucidum and stratum corneum layers of the epidermis . All parts of the skin involved in grasping are covered by papillary ridges ( fingerprints ) acting as friction pads. In contrast, the hairy skin on the dorsal side is thin, soft, and pliable, so that the skin can recoil when
SECTION 50
#17327972165687644-523: The ulnar nerve may result in a condition in which some of the fingers cannot be flexed. A common fracture of the hand is a scaphoid fracture —a fracture of the scaphoid bone , one of the carpal bones. This is the commonest carpal bone fracture and can be slow to heal due to a limited blood flow to the bone. There are various types of fracture to the base of the thumb; these are known as Rolando fractures , Bennet's fracture , and Gamekeeper's thumb . Another common fracture, known as Boxer's fracture ,
7791-415: The " Dynasty of Isin " in the Sumerian king list, ending with the rise of Babylonia under Hammurabi c. 1800 BC. Later rulers who dominated Assyria and Babylonia occasionally assumed the old Sargonic title "King of Sumer and Akkad", such as Tukulti-Ninurta I of Assyria after c. 1225 BC. Uruk, one of Sumer's largest cities, has been estimated to have had a population of 50,000–80,000 at its height. Given
7938-535: The 1:4 type or four-beads abacus similar to the modern abacus including the shape of the beads commonly known as Japanese-style abacus. In the early Ming dynasty , the abacus began to appear in a 1:5 ratio. The upper deck had one bead and the bottom had five beads. In the late Ming dynasty, the abacus styles appeared in a 2:5 ratio. The upper deck had two beads, and the bottom had five. Various calculation techniques were devised for Suanpan enabling efficient calculations. Some schools teach students how to use it. In
8085-435: The Akkadian and Ur III phases, there was a shift from the cultivation of wheat to the more salt-tolerant barley , but this was insufficient, and during the period from 2100 BC to 1700 BC, it is estimated that the population in this area declined by nearly three-fifths. This greatly upset the balance of power within the region, weakening the areas where Sumerian was spoken, and comparatively strengthening those where Akkadian
8232-515: The Chinese, Korean, and Japanese models, the Roman model used grooves, presumably making arithmetic calculations much slower.) Another possible source of the suanpan is Chinese counting rods , which operated with a decimal system but lacked the concept of zero as a placeholder. The zero was probably introduced to the Chinese in the Tang dynasty (618–907) when travel in the Indian Ocean and
8379-528: The Sumerian king list whose name is known from any other legendary source is Etana , 13th king of the first dynasty of Kish . The earliest king authenticated through archaeological evidence is Enmebaragesi of Kish (Early Dynastic I), whose name is mentioned in the Epic of Gilgamesh —leading to the suggestion that Gilgamesh himself might have been a historical king of Uruk. As the Epic of Gilgamesh shows, this period
8526-421: The Sumerians is not known, but the people of Sumer referred to themselves as "Black-Headed Ones" or "Black-Headed People" ( Sumerian : 𒊕 𒈪 , romanized: sag̃-gíg , lit. ''head" + "black'', or 𒊕 𒈪 𒂵 , sag̃-gíg-ga , phonetically /saŋ ɡi ɡa/ , lit. "head" + "black" + relative marker). For example, the Sumerian king Shulgi described himself as "the king of
8673-767: The Sumerians’ sphere of influence (ordered from south to north): Apart from Mari, which lies full 330 kilometres (205 miles) north-west of Agade, but which is credited in the king list as having exercised kingship in the Early Dynastic II period, and Nagar, an outpost, these cities are all in the Euphrates-Tigris alluvial plain, south of Baghdad in what are now the Bābil , Diyala , Wāsit , Dhi Qar , Basra , Al-Muthannā and Al-Qādisiyyah governorates of Iraq . The Sumerian city-states rose to power during
8820-473: The Ubaid period to the Uruk period is marked by a gradual shift from painted pottery domestically produced on a slow wheel to a great variety of unpainted pottery mass-produced by specialists on fast wheels. The Uruk period is a continuation and an outgrowth of Ubaid with pottery being the main visible change. By the time of the Uruk period, c. 4100–2900 BC calibrated, the volume of trade goods transported along
8967-509: The Uruk period coincided with the Piora oscillation , a dry period from c. 3200–2900 BC that marked the end of a long wetter, warmer climate period from about 9,000 to 5,000 years ago, called the Holocene climatic optimum . The dynastic period begins c. 2900 BC and was associated with a shift from the temple establishment headed by council of elders led by a priestly "En" (a male figure when it
SECTION 60
#17327972165689114-422: The Uruk period were probably theocratic and were most likely headed by a priest-king ( ensi ), assisted by a council of elders, including both men and women. It is quite possible that the later Sumerian pantheon was modeled upon this political structure. There was little evidence of organized warfare or professional soldiers during the Uruk period, and towns were generally unwalled. During this period Uruk became
9261-592: The abacus as a metaphor for human behavior, stating "that men that sometimes stood for more and sometimes for less" like the pebbles on an abacus. The Greek abacus was a table of wood or marble, pre-set with small counters in wood or metal for mathematical calculations. This Greek abacus was used in Achaemenid Persia, the Etruscan civilization , Ancient Rome, and the Western Christian world until
9408-445: The abacus is called soroban ( 算盤, そろばん , lit. "counting tray"). It was imported from China in the 14th century. It was probably in use by the working class a century or more before the ruling class adopted it, as the class structure obstructed such changes. The 1:4 abacus, which removes the seldom-used second and fifth bead, became popular in the 1940s. Today's Japanese abacus is a 1:4 type, four-bead abacus, introduced from China in
9555-488: The abacus is often taught to these students in early grades. Blind students can also complete mathematical assignments using a braille-writer and Nemeth code (a type of braille code for mathematics) but large multiplication and long division problems are tedious. The abacus gives these students a tool to compute mathematical problems that equals the speed and mathematical knowledge required by their sighted peers using pencil and paper. Many blind people find this number machine
9702-500: The abacus was used for more complex operations, i.e. cube roots, Feynman won easily. However, the number chosen at random was close to a number Feynman happened to know was an exact cube, allowing him to use approximate methods. Learning how to calculate with the abacus may improve capacity for mental calculation. Abacus-based mental calculation (AMC), which was derived from the abacus, is the act of performing calculations, including addition, subtraction, multiplication, and division, in
9849-521: The abacus with modifications, it became widely used in Europe again during the 11th century It used beads on wires, unlike the traditional Roman counting boards, which meant the abacus could be used much faster and was more easily moved. The earliest known written documentation of the Chinese abacus dates to the 2nd century BC. The Chinese abacus, also known as the suanpan (算盤/算盘, lit. "calculating tray"), comes in various lengths and widths, depending on
9996-402: The back of the hand), the deep palmar arch , and the superficial palmar arch . Together these three arches and their anastomoses provide oxygenated blood to the palm, the fingers, and the thumb. The hand is drained by the dorsal venous network of the hand with deoxygenated blood leaving the hand via the cephalic vein and the basilic vein . The glabrous (hairless) skin on the front of
10143-459: The bead frame shown, the gap between the 5th and 6th wire, corresponding to the color change between the 5th and the 6th bead on each wire, suggests the latter use. Teaching multiplication, e.g. 6 times 7, may be represented by shifting 7 beads on 6 wires. The red-and-white abacus is used in contemporary primary schools for a wide range of number-related lessons. The twenty bead version, referred to by its Dutch name rekenrek ("calculating frame"),
10290-418: The bones of the forearm, and a distal row ( trapezium , trapezoid , capitate and hamate ), which articulates with the bases of the five metacarpal bones of the hand. The heads of the metacarpals will each in turn articulate with the bases of the proximal phalanx of the fingers and thumb. These articulations with the fingers are the metacarpophalangeal joints known as the knuckles. At the palmar aspect of
10437-430: The canals and rivers of southern Mesopotamia facilitated the rise of many large, stratified , temple-centered cities, with populations of over 10,000 people, where centralized administrations employed specialized workers. It is fairly certain that it was during the Uruk period that Sumerian cities began to make use of slave labour captured from the hill country, and there is ample evidence for captured slaves as workers in
10584-465: The countries around them – India, China, and the Roman Empire – which is how the abacus may have been exported to other countries. The earliest archaeological evidence for the use of the Greek abacus dates to the 5th century BC. Demosthenes (384–322 BC) complained that the need to use pebbles for calculations was too difficult. A play by Alexis from the 4th century BC mentions an abacus and pebbles for accounting, and both Diogenes and Polybius use
10731-437: The densest areas of nerve endings in the body, and are the richest source of tactile feedback. They also have the greatest positioning capability of the body; thus, the sense of touch is intimately associated with hands. Like other paired organs (eyes, feet, legs) each hand is dominantly controlled by the opposing brain hemisphere , so that handedness —the preferred hand choice for single-handed activities such as writing with
10878-519: The disorders that can cause this is Catel-Manzke syndrome . The fingers may be fused in a disorder known as syndactyly . Or there may be an absence of one or more central fingers—a condition known as ectrodactyly . Additionally, some people are born without one or both hands ( amelia ). Hereditary multiple exostoses of the forearm—also known as hereditary multiple osteochondromas—is another cause of hand and forearm deformity in children and adults. There are several cutaneous conditions that can affect
11025-718: The downfall of the Akkadian Empire at the hands of Gutians , another native Sumerian ruler, Gudea of Lagash, rose to local prominence and continued the practices of the Sargonic kings ' claims to divinity. The previous Lagash dynasty, Gudea and his descendants also promoted artistic development and left a large number of archaeological artifacts. Later, the Third Dynasty of Ur under Ur-Nammu and Shulgi (c. 2112–2004 BC, middle chronology), whose power extended as far as southern Assyria , has been erroneously called
11172-754: The earliest texts. Artifacts, and even colonies of this Uruk civilization have been found over a wide area—from the Taurus Mountains in Turkey , to the Mediterranean Sea in the west, and as far east as western Iran . The Uruk period civilization, exported by Sumerian traders and colonists, like that found at Tell Brak , had an effect on all surrounding peoples, who gradually evolved their own comparable, competing economies and cultures. The cities of Sumer could not maintain remote, long-distance colonies by military force. Sumerian cities during
11319-447: The exact number varies between people: whereas a pair of sesamoid bones are found at virtually all thumb metacarpophalangeal joints, sesamoid bones are also common at the interphalangeal joint of the thumb (72.9%) and at the metacarpophalangeal joints of the little finger (82.5%) and the index finger (48%). In rare cases, sesamoid bones have been found in all the metacarpophalangeal joints and all distal interphalangeal joints except that of
11466-426: The fingers and toes". The ratio of the length of the index finger to the length of the ring finger in adults is affected by the level of exposure to male sex hormones of the embryo in utero . This digit ratio is below 1 for both sexes but it is lower in males than in females on average. A number of genetic disorders affect the hand. Polydactyly is the presence of more than the usual number of fingers. One of
11613-434: The fingers are stretched. On the dorsal side, the skin can be moved across the hand up to 3 cm (1.2 in); an important input the cutaneous mechanoreceptors . The web of the hand is a "fold of skin which connects the digits". These webs, located between each set of digits, are known as skin folds (interdigital folds or plica interdigitalis). They are defined as "one of the folds of skin, or rudimentary web, between
11760-471: The first empires known to history was that of Eannatum of Lagash, who annexed practically all of Sumer, including Kish, Uruk, Ur , and Larsa , and reduced to tribute the city-state of Umma , arch-rival of Lagash. In addition, his realm extended to parts of Elam and along the Persian Gulf . He seems to have used terror as a matter of policy. Eannatum's Stele of the Vultures depicts vultures pecking at
11907-417: The first metacarpophalangeal joints are small, almost spherical bones called the sesamoid bones. The fourteen phalanges make up the fingers and thumb, and are numbered I-V (thumb to little finger) when the hand is viewed from an anatomical position (palm up). The four fingers each consist of three phalanx bones: proximal, middle, and distal. The thumb only consists of a proximal and distal phalanx. Together with
12054-540: The first state that successfully united larger parts of Mesopotamia in the 23rd century BC. After the Gutian period , the Ur III kingdom similarly united parts of northern and southern Mesopotamia. It ended in the face of Amorite incursions at the beginning of the second millennium BC. The Amorite "dynasty of Isin " persisted until c. 1700 BC , when Mesopotamia was united under Babylonian rule. The Ubaid period
12201-528: The form of several yupanas, researchers found that calculations were based using the Fibonacci sequence 1, 1, 2, 3, 5 and powers of 10, 20, and 40 as place values for the different fields in the instrument. Using the Fibonacci sequence would keep the number of grains within any one field at a minimum. The Russian abacus, the schoty ( Russian : счёты , plural from Russian : счёт , counting), usually has
12348-739: The four quarters, the pastor of the black-headed people". The Akkadians also called the Sumerians "black-headed people", or ṣalmat-qaqqadi , in the Semitic Akkadian language. The Akkadians, the East Semitic-speaking people who later conquered the Sumerian city-states , gave Sumer its main historical name, but the phonological development of the term šumerû is uncertain. Hebrew שִׁנְעָר Šinʿar , Egyptian Sngr , and Hittite Šanhar(a) , all referring to southern Mesopotamia, could be western variants of Sumer . Most historians have suggested that Sumer
12495-546: The fundamentals of mathematics to children in most countries. The word abacus dates to at least 1387 AD when a Middle English work borrowed the word from Latin that described a sandboard abacus. The Latin word is derived from ancient Greek ἄβαξ ( abax ) which means something without a base, and colloquially, any piece of rectangular material. Alternatively, without reference to ancient texts on etymology, it has been suggested that it means "a square tablet strewn with dust", or "drawing-board covered with dust (for
12642-576: The genomes of Natufian and Pre-Pottery Neolithic culture-bearers. Craniometric analysis has also suggested an affinity between Natufians and ancient North Africans. Some scholars associate the Sumerians with the Hurrians and Urartians , and suggest the Caucasus as their homeland. This is not generally accepted. Based on mentions of Dilmun as the “home city of the land of Sumer” in Sumerian legends and literature, other scholars have suggested
12789-418: The groove on the dorsum of inferior side of ulna. The hand is innervated by the radial , median , and ulnar nerves . The radial nerve supplies the finger extensors and the thumb abductor , thus the muscles that extends at the wrist and metacarpophalangeal joints (knuckles); and that abducts and extends the thumb. The median nerve supplies the flexors of the wrist and digits, the abductors and opponens of
12936-456: The hand including the nails . The autoimmune disease rheumatoid arthritis can affect the hand, particularly the joints of the fingers. Some conditions can be treated by hand surgery . These include carpal tunnel syndrome , a painful condition of the hand and fingers caused by compression of the median nerve , and Dupuytren's contracture , a condition in which fingers bend towards the palm and cannot be straightened. Similarly, injury to
13083-457: The hand of modern humans have shown that they are consistent with the stresses and requirements associated with the effective use of paleolithic stone tools. It is possible that the refinement of the bipedal posture in the earliest hominids evolved to facilitate the use of the trunk as leverage in accelerating the hand. While the human hand has unique anatomical features, including a longer thumb and fingers that can be controlled individually to
13230-448: The hand, that of the thumb is the most mobile (and the least longitudinal). While the ray formed by the little finger and its associated metacarpal bone still offers some mobility, the remaining rays are firmly rigid. The phalangeal joints of the index finger, however, offer some independence to its finger, due to the arrangement of its flexor and extension tendons. The carpal bones form two transversal rows, each forming an arch concave on
13377-400: The hand, the palm, is relatively thick and can be bent along the hand's flexure lines where the skin is tightly bound to the underlying tissue and bones. Compared to the rest of the body's skin, the hands' palms (as well as the soles of the feet ) are usually lighter—and even much lighter in dark-skinned individuals, compared to the other side of the hand. Indeed, genes specifically expressed in
13524-461: The human hand are plesiomorphic (shared by both ancestors and extant primate species); the elongated thumbs and short hands more closely resemble the hand proportions of Miocene apes than those of extant primates. Humans did not evolve from knuckle-walking apes, and chimpanzees and gorillas independently acquired elongated metacarpals as part of their adaptation to their modes of locomotion. Several primitive hand features most likely present in
13671-413: The human hand include: There are five digits attached to the hand, notably with a nail fixed to the end in place of the normal claw . The four fingers can be folded over the palm which allows the grasping of objects. Each finger, starting with the one closest to the thumb, has a colloquial name to distinguish it from the others: The thumb (connected to the first metacarpal bone and trapezium )
13818-413: The human hand, including pentadactyly (having five fingers), the hairless skin of the palm and fingers, and the os centrale found in human embryos, prosimians, and apes. Furthermore, the precursors of the intrinsic muscles of the hand are present in the earliest fishes, reflecting that the hand evolved from the pectoral fin and thus is much older than the arm in evolutionary terms. The proportions of
13965-471: The idea of a Proto-Euphratean language or one substrate language; they think the Sumerian language may originally have been that of the hunting and fishing peoples who lived in the marshland and the Eastern Arabia littoral region and were part of the Arabian bifacial culture. Juris Zarins believes the Sumerians lived along the coast of Eastern Arabia , today's Persian Gulf region, before it
14112-450: The index and middle finger, it forms the dynamic tridactyl configuration responsible for most grips not requiring force. The ring and little fingers are more static, a reserve ready to interact with the palm when great force is needed. The muscles acting on the hand can be subdivided into two groups: the extrinsic and intrinsic muscle groups. The extrinsic muscle groups are the long flexors and extensors . They are called extrinsic because
14259-421: The index finger. For example, in some individuals, the ulnar nerve supplies the entire ring finger and the ulnar side of the middle finger, whilst, in others, the median nerve supplies the entire ring finger. The hand is supplied with blood from two arteries, the ulnar artery and the radial artery . These arteries form three arches over the dorsal and palmar aspects of the hand, the dorsal carpal arch (across
14406-480: The interlocking shapes of the carpal bones, and the wrist is therefore more stable in flexion than in extension. The distal carpal arch affects the function of the CMC joints and the hands, but not the function of the wrist or the proximal carpal arch. The ligaments that maintain the distal carpal arches are the transverse carpal ligament and the intercarpal ligaments (also oriented transversally). These ligaments also form
14553-514: The late 4th millennium BC, Sumer was divided into many independent city-states , which were divided by canals and boundary stones. Each was centered on a temple dedicated to the particular patron god or goddess of the city and ruled over by a priestly governor ( ensi ) or by a king ( lugal ) who was intimately tied to the city's religious rites. An incomplete list of cities that may have been visited, interacted and traded with, invaded, conquered, destroyed, occupied, colonized by and/or otherwise within
14700-420: The long finger. The articulations are: The fixed and mobile parts of the hand adapt to various everyday tasks by forming bony arches: longitudinal arches (the rays formed by the finger bones and their associated metacarpal bones), transverse arches (formed by the carpal bones and distal ends of the metacarpal bones), and oblique arches (between the thumb and four fingers): Of the longitudinal arches or rays of
14847-588: The long scroll Along the River During the Qingming Festival painted by Zhang Zeduan during the Song dynasty (960–1297), a suanpan is clearly visible beside an account book and doctor's prescriptions on the counter of an apothecary 's (Feibao). The similarity of the Roman abacus to the Chinese one suggests that one could have inspired the other, given evidence of a trade relationship between
14994-489: The marshlands, who may have been the ancestors of the Sumerians. Reliable historical records begin with Enmebaragesi ( Early Dynastic I ). The Sumerians progressively lost control to Semitic states from the northwest. Sumer was conquered by the Semitic-speaking kings of the Akkadian Empire around 2270 BC ( short chronology ), but Sumerian continued as a sacred language . Native Sumerian rule re-emerged for about
15141-402: The mind by manipulating an imagined abacus. It is a high-level cognitive skill that runs calculations with an effective algorithm. People doing long-term AMC training show higher numerical memory capacity and experience more effectively connected neural pathways. They are able to retrieve memory to deal with complex processes. AMC involves both visuospatial and visuomotor processing that generate
15288-429: The most urbanized city in the world, surpassing for the first time 50,000 inhabitants. The ancient Sumerian king list includes the early dynasties of several prominent cities from this period. The first set of names on the list is of kings said to have reigned before a major flood occurred. These early names may be fictional, and include some legendary and mythological figures, such as Alulim and Dumizid . The end of
15435-456: The motoneurons of the hand muscles; placing the hands "closer" to the brain. The recent evolution of the human hand is thus a direct result of the development of the central nervous system , and the hand, therefore, is a direct tool of our consciousness—the main source of differentiated tactile sensations—and a precise working organ enabling gestures—the expressions of our personalities. There are nevertheless several primitive features left in
15582-455: The muscle belly is located on the forearm. The intrinsic muscle groups are the thenar (thumb) and hypothenar (little finger) muscles; the interosseous muscles ( four dorsally and three volarly ) originating between the metacarpal bones; and the lumbrical muscles arising from the deep flexor (and are special because they have no bony origin) to insert on the dorsal extensor hood mechanism. The fingers have two long flexors, located on
15729-467: The north of Mesopotamia after perfecting irrigation agriculture there. The Ubaid period pottery of southern Mesopotamia has been connected via Choga Mami transitional ware, to the pottery of the Samarra period culture ( c. 5700 –4900 BC C-14 ) in the north, who were the first to practice a primitive form of irrigation agriculture along the middle Tigris River and its tributaries. The connection
15876-402: The north. Ecologically, the agricultural productivity of the Sumerian lands was being compromised as a result of rising salinity. Soil salinity in this region had been long recognized as a major problem. Poorly drained irrigated soils, in an arid climate with high levels of evaporation, led to the buildup of dissolved salts in the soil, eventually reducing agricultural yields severely. During
16023-413: The operator. It usually has more than seven rods. There are two beads on each rod in the upper deck and five beads each in the bottom one, to represent numbers in a bi-quinary coded decimal -like system. The beads are usually rounded and made of hardwood . The beads are counted by moving them up or down towards the beam; beads moved toward the beam are counted, while those moved away from it are not. One of
16170-551: The other cities in Sumer, and the large agricultural population, a rough estimate for Sumer's population might be 0.8 million to 1.5 million. The world population at this time has been estimated at 27 million. The Sumerians spoke a language isolate . A number of linguists have claimed to be able to detect a substrate language of unknown classification beneath Sumerian, because names of some of Sumer's major cities are not Sumerian, revealing influences of earlier inhabitants. However,
16317-403: The palmar gutter deepens. The central-most metacarpal (middle finger) is the most rigid. It and its two neighbors are tied to the carpus by the interlocking shapes of the metacarpal bones. The thumb metacarpal only articulates with the trapezium and is therefore completely independent, while the fifth metacarpal (little finger) is semi-independent with the fourth metacarpal (ring finger) which forms
16464-407: The palmar side of the thumb, index, middle, and half ring fingers. Dorsal branches innervates the distal phalanges of the index, middle, and half ring fingers. The ulnar nerve supplies the ulnar third of the hand, both at the palm and the back of the hand, and the little and half ring fingers. There is a considerable variation to this general pattern, except for the little finger and volar surface of
16611-410: The palmar side. Because the proximal arch simultaneously has to adapt to the articular surface of the radius and to the distal carpal row, it is by necessity flexible. In contrast, the capitate, the "keystone" of the distal arch, moves together with the metacarpal bones and the distal arch is therefore rigid. The stability of these arches is more dependent of the ligaments and capsules of the wrist than of
16758-606: The pebbles from right to left, opposite in direction to the Greek left-to-right method. Archaeologists have found ancient disks of various sizes that are thought to have been used as counters. However, wall depictions of this instrument are yet to be discovered. At around 600 BC, Persians first began to use the abacus, during the Achaemenid Empire . Under the Parthian , Sassanian , and Iranian empires, scholars concentrated on exchanging knowledge and inventions with
16905-415: The phalanges of the fingers and thumb these metacarpal bones form five rays or poly-articulated chains. Because supination and pronation (rotation about the axis of the forearm) are added to the two axes of movements of the wrist, the ulna and radius are sometimes considered part of the skeleton of the hand. There are numerous sesamoid bones in the hand, small ossified nodes embedded in tendons;
17052-518: The possibility that the Sumerians originated from Dilmun, which was theorized to be the island of Bahrain in the Persian Gulf. In Sumerian mythology, Dilmun was also mentioned as the home of deities such as Enki . The status of Dilmun as the Sumerians’ ancestral homeland has not been established, but archaeologists have found evidence of civilization in Bahrain, namely the existence of Mesopotamian-style round disks. A prehistoric people who lived in
17199-509: The post-Biblical sense "sand used as a writing surface"). Both abacuses and abaci are used as plurals. The user of an abacus is called an abacist . The Sumerian abacus appeared between 2700 and 2300 BC. It held a table of successive columns which delimited the successive orders of magnitude of their sexagesimal (base 60) number system. Some scholars point to a character in Babylonian cuneiform that may have been derived from
17346-469: The prehistoric Ubaid and Uruk periods. Sumerian written history reaches back to the 27th century BC and before, but the historical record remains obscure until the Early Dynastic III period, c. 23rd century BC , when the language of the written records becomes easier to decipher, which has allowed archaeologists to read contemporary records and inscriptions. The Akkadian Empire was
17493-524: The region before the Sumerians have been termed the " Proto-Euphrateans " or " Ubaidians ", and are theorized to have evolved from the Samarra culture of northern Mesopotamia. The Ubaidians, though never mentioned by the Sumerians themselves, are assumed by modern-day scholars to have been the first civilizing force in Sumer. They drained the marshes for agriculture , developed trade, and established industries, including weaving , leatherwork , metalwork , masonry , and pottery . Some scholars contest
17640-402: The right. During manipulation, beads are moved to the left. For easy viewing, the middle 2 beads on each wire (the 5th and 6th bead) usually are of a different color from the other eight. Likewise, the left bead of the thousands wire (and the million wire, if present) may have a different color. The Russian abacus was in use in shops and markets throughout the former Soviet Union , and its usage
17787-610: The same time, in order to make the multiplication and division digits consistently use the division multiplication. Later, Japan had a 3:5 abacus called 天三算盤, which is now in the Ize Rongji collection of Shansi Village in Yamagata City. Japan also used a 2:5 type abacus. The four-bead abacus spread, and became common around the world. Improvements to the Japanese abacus arose in various places. In China, an abacus with an aluminium frame and plastic beads has been used. The file
17934-433: The scribes. Gelb and Westenholz differentiate three stages of Old Akkadian: that of the pre-Sargonic era, that of the Akkadian empire, and that of the Ur III period that followed it. Akkadian and Sumerian coexisted as vernacular languages for about one thousand years, but by around 1800 BC, Sumerian was becoming more of a literary language familiar mainly only to scholars and scribes. Thorkild Jacobsen has argued that there
18081-665: The severed heads and other body parts of his enemies. His empire collapsed shortly after his death. Later, Lugal-zage-si , the priest-king of Umma, overthrew the primacy of the Lagash dynasty in the area, then conquered Uruk, making it his capital, and claimed an empire extending from the Persian Gulf to the Mediterranean. He was the last ethnically Sumerian king before Sargon of Akkad . The Akkadian Empire dates to c. 2234 –2154 BC ( middle chronology ), founded by Sargon of Akkad . The Eastern Semitic Akkadian language
18228-487: The shorter grooves denote fives (five units, five tens, etc.) resembling a bi-quinary coded decimal system related to the Roman numerals . The short grooves on the right may have been used for marking Roman "ounces" (i.e. fractions). The Roman system of 'counter casting' was used widely in medieval Europe, and persisted in limited use into the nineteenth century. Wealthy abacists used decorative minted counters, called jetons . Due to Pope Sylvester II 's reintroduction of
18375-691: The south of Mesopotamia as the Babylonian Empire , just as the Old Assyrian Empire had already done in the north from the late 21st century BC. The Sumerian language continued as a sacerdotal language taught in schools in Babylonia and Assyria, much as Latin was used in the Medieval period, for as long as cuneiform was used. This period is generally taken to coincide with a major shift in population from southern Mesopotamia toward
18522-403: The tendons of these form the anatomical snuff box . Also, the index finger and the little finger have an extra extensor used, for instance, for pointing. The extensors are situated within 6 separate compartments. The first four compartments are located in the grooves present on the dorsum of inferior side of radius while the 5th compartment is in between radius and ulna. The 6th compartment is in
18669-410: The term hand in this sense to distinguish the terminations of the front paws from the hind ones is an example of anthropomorphism . The only true grasping hands appear in the mammalian order of primates . Hands must also have opposable thumbs , as described later in the text. The hand is located at the distal end of each arm. Apes and monkeys are sometimes described as having four hands, because
18816-405: The thumb in opposition, making grasping possible. The extensors are located on the back of the forearm and are connected in a more complex way than the flexors to the dorsum of the fingers. The tendons unite with the interosseous and lumbrical muscles to form the extensorhood mechanism. The primary function of the extensors is to straighten out the digits. The thumb has two extensors in the forearm;
18963-415: The thumb is included as one of the fingers . It has 27 bones, not including the sesamoid bone , the number of which varies among people, 14 of which are the phalanges ( proximal , intermediate and distal ) of the fingers and thumb. The metacarpal bones connect the fingers and the carpal bones of the wrist . Each human hand has five metacarpals and eight carpal bones. Fingers contain some of
19110-461: The thumb, the first and second lumbrical. The ulnar nerve supplies the remaining intrinsic muscles of the hand. All muscles of the hand are innervated by the brachial plexus (C5–T1) and can be classified by innervation: The radial nerve supplies the skin on the back of the hand from the thumb to the ring finger and the dorsal aspects of the index, middle, and half ring fingers as far as the proximal interphalangeal joints. The median nerve supplies
19257-410: The toes are long and the hallux is opposable and looks more like a thumb , thus enabling the feet to be used as hands. The word "hand" is sometimes used by evolutionary anatomists to refer to the appendage of digits on the forelimb such as when researching the homology between the three digits of the bird hand and the dinosaur hand. An adult human male's hand weighs about a pound. Areas of
19404-468: The top beads is 5, while one of the bottom beads is 1. Each rod has a number under it, showing the place value. The suanpan can be reset to the starting position instantly by a quick movement along the horizontal axis to spin all the beads away from the horizontal beam at the center. The prototype of the Chinese abacus appeared during the Han dynasty , and the beads are oval. The Song dynasty and earlier used
19551-435: The underside of the forearm. They insert by tendons to the phalanges of the fingers. The deep flexor attaches to the distal phalanx, and the superficial flexor attaches to the middle phalanx. The flexors allow for the actual bending of the fingers. The thumb has one long flexor and a short flexor in the thenar muscle group. The human thumb also has other muscles in the thenar group ( opponens and abductor brevis muscle ), moving
19698-527: The use of mathematics)" (the exact shape of the Latin perhaps reflects the genitive form of the Greek word, ἄβακoς ( abakos )). While the table strewn with dust definition is popular, some argue evidence is insufficient for that conclusion. Greek ἄβαξ probably borrowed from a Northwest Semitic language like Phoenician , evidenced by a cognate with the Hebrew word ʾābāq ( אבק ), or "dust" (in
19845-499: The valleys of the Tigris and Euphrates rivers, Sumerian farmers grew an abundance of grain and other crops, a surplus which enabled them to form urban settlements. The world's earliest known texts come from the Sumerian cities of Uruk and Jemdet Nasr , and date to between c. 3350 – c. 2500 BC , following a period of proto-writing c. 4000 – c. 2500 BC . The term "Sumer" ( Akkadian : 𒋗𒈨𒊒 , romanized: šumeru ) comes from
19992-407: The value of the respective beads of the upper rows, it is enough to multiply by 20 (by each row), the value of the corresponding count in the first row. The device featured 13 rows with 7 beads, 91 in total. This was a basic number for this culture. It had a close relation to natural phenomena, the underworld, and the cycles of the heavens. One Nepōhualtzintzin (91) represented the number of days that
20139-465: The visual abacus and move the imaginary beads. Since it only requires that the final position of beads be remembered, it takes less memory and less computation time. The binary abacus is used to explain how computers manipulate numbers. The abacus shows how numbers, letters, and signs can be stored in a binary system on a computer, or via ASCII . The device consists of a series of beads on parallel wires arranged in three separate rows. The beads represent
20286-610: Was a temple for a goddess, or a female figure when headed by a male god) towards a more secular Lugal (Lu = man, Gal = great) and includes such legendary patriarchal figures as Dumuzid , Lugalbanda and Gilgamesh —who reigned shortly before the historic record opens c. 2900 BC, when the now deciphered syllabic writing started to develop from the early pictograms. The center of Sumerian culture remained in southern Mesopotamia, even though rulers soon began expanding into neighboring areas, and neighboring Semitic groups adopted much of Sumerian culture for their own. The earliest dynastic king on
20433-410: Was associated with increased war. Cities became walled, and increased in size as undefended villages in southern Mesopotamia disappeared. Both Enmerkar and Gilgamesh are credited with having built the walls of Uruk. The dynasty of Lagash (c. 2500–2270 BC), though omitted from the king list, is well attested through several important monuments and many archaeological finds. Although short-lived, one of
20580-479: Was derived from the Samarran culture from northern Mesopotamia. It is not known whether or not these were the actual Sumerians who are identified with the later Uruk culture. The story of the passing of the gifts of civilization ( me ) to Inanna , goddess of Uruk and of love and war, by Enki , god of wisdom and chief god of Eridu, may reflect the transition from Eridu to Uruk. The archaeological transition from
20727-532: Was first permanently settled between c. 5500 – c. 3300 BC by a West Asian people who spoke the Sumerian language (pointing to the names of cities, rivers, basic occupations, etc., as evidence), a non-Semitic and non- Indo-European agglutinative language isolate . Others have suggested that the Sumerians were a North African people who migrated from the Green Sahara into
20874-750: Was flooded at the end of the Ice Age . Sumerian civilization took form in the Uruk period (4th millennium BC), continuing into the Jemdet Nasr and Early Dynastic periods. The Sumerian city of Eridu , on the coast of the Persian Gulf, is considered to have been one of the oldest cities , where three separate cultures may have fused: that of peasant Ubaidian farmers, living in mud-brick huts and practicing irrigation; that of mobile nomadic Semitic pastoralists living in black tents and following herds of sheep and goats; and that of fisher folk, living in reed huts in
21021-506: Was not allowed. The rediscovery of the Nepōhualtzintzin was due to the Mexican engineer David Esparza Hidalgo, who in his travels throughout Mexico found diverse engravings and paintings of this instrument and reconstructed several of them in gold, jade, encrustations of shell, etc. Very old Nepōhualtzintzin are attributed to the Olmec culture, and some bracelets of Mayan origin, as well as
21168-590: Was something new. Poncelet used it, not for any applied purpose, but as a teaching and demonstration aid. The Turks and the Armenian people used abacuses similar to the Russian schoty. It was named a coulba by the Turks and a choreb by the Armenians. Around the world, abacuses have been used in pre-schools and elementary schools as an aid in teaching the numeral system and arithmetic . In Western countries,
21315-503: Was taught in most schools until the 1990s. Even the 1874 invention of mechanical calculator , Odhner arithmometer , had not replaced them in Russia. According to Yakov Perelman , some businessmen attempting to import calculators into the Russian Empire were known to leave in despair after watching a skilled abacus operator. Likewise, the mass production of Felix arithmometers since 1924 did not significantly reduce abacus use in
21462-525: Was taught in the Calmecac to the temalpouhqueh Nahuatl pronunciation: [temaɬˈpoʍkeʔ] , who were students dedicated to taking the accounts of skies, from childhood. The Nepōhualtzintzin was divided into two main parts separated by a bar or intermediate cord. In the left part were four beads. Beads in the first row have unitary values (1, 2, 3, and 4), and on the right side, three beads had values of 5, 10, and 15, respectively. In order to know
21609-483: Was the major language. Henceforth, Sumerian remained only a literary and liturgical language, similar to the position occupied by Latin in medieval Europe. Following an Elamite invasion and sack of Ur during the rule of Ibbi-Sin (c. 2028–2004 BC), Sumer came under Amorite rule (taken to introduce the Middle Bronze Age ). The independent Amorite states of the 20th to 18th centuries are summarized as
#567432