Order of magnitude is a concept used to discuss the scale of numbers in relation to one another.
56-445: To help compare different orders of magnitude , the following lists describe various mass levels between 10 kg and 10 kg. The least massive thing listed here is a graviton , and the most massive thing is the observable universe . Typically, an object having greater mass will also have greater weight (see mass versus weight ), especially if the objects are subject to the same gravitational field strength . The table at right
112-445: A . To confirm our expectation that 1 − 2 and 4 − 5 denote the same number, we define an equivalence relation ~ on these pairs with the following rule: precisely when Addition and multiplication of integers can be defined in terms of the equivalent operations on the natural numbers; by using [( a , b )] to denote the equivalence class having ( a , b ) as a member, one has: The negation (or additive inverse) of an integer
168-469: A factor of 100 5 ≈ 2.512 {\displaystyle {\sqrt[{5}]{100}}\approx 2.512} greater than the previous level. Thus, a level being 5 magnitudes brighter than another indicates that it is a factor of ( 100 5 ) 5 = 100 {\displaystyle ({\sqrt[{5}]{100}})^{5}=100} times brighter: that is, two base 10 orders of magnitude. This series of magnitudes forms
224-520: A fractional component . For example, 21, 4, 0, and −2048 are integers, while 9.75, 5 + 1 / 2 , 5/4, and √ 2 are not. The integers form the smallest group and the smallest ring containing the natural numbers . In algebraic number theory , the integers are sometimes qualified as rational integers to distinguish them from the more general algebraic integers . In fact, (rational) integers are algebraic integers that are also rational numbers . The word integer comes from
280-454: A calculator to be 6. An order of magnitude is an approximate position on a logarithmic scale . An order-of-magnitude estimate of a variable, whose precise value is unknown, is an estimate rounded to the nearest power of ten. For example, an order-of-magnitude estimate for a variable between about 3 billion and 30 billion (such as the human population of the Earth ) is 10 billion . To round
336-473: A few basic operations (e.g., zero , succ , pred ) and using natural numbers , which are assumed to be already constructed (using the Peano approach ). There exist at least ten such constructions of signed integers. These constructions differ in several ways: the number of basic operations used for the construction, the number (usually, between 0 and 2), and the types of arguments accepted by these operations;
392-458: A finite sum 1 + 1 + ... + 1 or (−1) + (−1) + ... + (−1) . In fact, Z {\displaystyle \mathbb {Z} } under addition is the only infinite cyclic group—in the sense that any infinite cyclic group is isomorphic to Z {\displaystyle \mathbb {Z} } . The first four properties listed above for multiplication say that Z {\displaystyle \mathbb {Z} } under multiplication
448-412: A logarithmic scale with a base of 100 5 {\displaystyle {\sqrt[{5}]{100}}} . The different decimal numeral systems of the world use a larger base to better envision the size of the number, and have created names for the powers of this larger base. The table shows what number the order of magnitude aim at for base 10 and for base 1 000 000 . It can be seen that
504-462: A number N {\displaystyle N} , the number is first expressed in the following form: where 1 10 ≤ a < 10 {\displaystyle {\frac {1}{\sqrt {10}}}\leq a<{\sqrt {10}}} , or approximately 0.316 ≲ a ≲ 3.16 {\displaystyle 0.316\lesssim a\lesssim 3.16} . Then, b {\displaystyle b} represents
560-402: A number to its nearest order of magnitude, one rounds its logarithm to the nearest integer. Thus 4 000 000 , which has a logarithm (in base 10) of 6.602, has 7 as its nearest order of magnitude, because "nearest" implies rounding rather than truncation. For a number written in scientific notation, this logarithmic rounding scale requires rounding up to the next power of ten when the multiplier
616-400: A set P − {\displaystyle P^{-}} which is disjoint from P {\displaystyle P} and in one-to-one correspondence with P {\displaystyle P} via a function ψ {\displaystyle \psi } . For example, take P − {\displaystyle P^{-}} to be
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#1732775802424672-426: A value of exactly 10 b {\displaystyle 10^{b}} (i.e., a = 1 {\displaystyle a=1} ) represents a geometric halfway point within the range of possible values of a {\displaystyle a} . Some use a simpler definition where 0.5 ≤ a < 5 {\displaystyle 0.5\leq a<5} . This definition has
728-433: Is a commutative monoid . However, not every integer has a multiplicative inverse (as is the case of the number 2), which means that Z {\displaystyle \mathbb {Z} } under multiplication is not a group. All the rules from the above property table (except for the last), when taken together, say that Z {\displaystyle \mathbb {Z} } together with addition and multiplication
784-422: Is a commutative ring with unity . It is the prototype of all objects of such algebraic structure . Only those equalities of expressions are true in Z {\displaystyle \mathbb {Z} } for all values of variables, which are true in any unital commutative ring. Certain non-zero integers map to zero in certain rings. The lack of zero divisors in the integers (last property in
840-422: Is a subset of the set of all rational numbers Q {\displaystyle \mathbb {Q} } , itself a subset of the real numbers R {\displaystyle \mathbb {R} } . Like the set of natural numbers, the set of integers Z {\displaystyle \mathbb {Z} } is countably infinite . An integer may be regarded as a real number that can be written without
896-419: Is an SI-compatible unit of mass equal to a megagram ( Mg ), or 10 kg. The unit is in common use for masses above about 10 kg and is often used with SI prefixes. For example, a gigagram ( Gg ) or 10 g is 10 tonnes, commonly called a kilotonne . Other units of mass are also in use. Historical units include the stone , the pound , the carat , and the grain . For subatomic particles, physicists use
952-488: Is based on the kilogram (kg), the base unit of mass in the International System of Units ( SI ). The kilogram is the only standard unit to include an SI prefix ( kilo- ) as part of its name. The gram (10 kg) is an SI derived unit of mass. However, the names of all SI mass units are based on gram , rather than on kilogram ; thus 10 kg is a megagram (10 g), not a * kilokilogram . The tonne (t)
1008-469: Is called the quotient and r is called the remainder of the division of a by b . The Euclidean algorithm for computing greatest common divisors works by a sequence of Euclidean divisions. The above says that Z {\displaystyle \mathbb {Z} } is a Euclidean domain . This implies that Z {\displaystyle \mathbb {Z} } is a principal ideal domain , and any positive integer can be written as
1064-475: Is equivalent to the statement that any Noetherian valuation ring is either a field —or a discrete valuation ring . In elementary school teaching, integers are often intuitively defined as the union of the (positive) natural numbers, zero , and the negations of the natural numbers. This can be formalized as follows. First construct the set of natural numbers according to the Peano axioms , call this P {\displaystyle P} . Then construct
1120-468: Is greater than zero , and negative if it is less than zero. Zero is defined as neither negative nor positive. The ordering of integers is compatible with the algebraic operations in the following way: Thus it follows that Z {\displaystyle \mathbb {Z} } together with the above ordering is an ordered ring . The integers are the only nontrivial totally ordered abelian group whose positive elements are well-ordered . This
1176-427: Is greater than the square root of ten (about 3.162). For example, the nearest order of magnitude for 1.7 × 10 is 8, whereas the nearest order of magnitude for 3.7 × 10 is 9. An order-of-magnitude estimate is sometimes also called a zeroth order approximation . An order of magnitude is an approximation of the logarithm of a value relative to some contextually understood reference value, usually 10, interpreted as
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#17327758024241232-401: Is identified with the class [( n ,0)] (i.e., the natural numbers are embedded into the integers by map sending n to [( n ,0)] ), and the class [(0, n )] is denoted − n (this covers all remaining classes, and gives the class [(0,0)] a second time since –0 = 0. Thus, [( a , b )] is denoted by If the natural numbers are identified with the corresponding integers (using
1288-437: Is not defined on Z {\displaystyle \mathbb {Z} } , the division "with remainder" is defined on them. It is called Euclidean division , and possesses the following important property: given two integers a and b with b ≠ 0 , there exist unique integers q and r such that a = q × b + r and 0 ≤ r < | b | , where | b | denotes the absolute value of b . The integer q
1344-431: Is obtained by reversing the order of the pair: Hence subtraction can be defined as the addition of the additive inverse: The standard ordering on the integers is given by: It is easily verified that these definitions are independent of the choice of representatives of the equivalence classes. Every equivalence class has a unique member that is of the form ( n ,0) or (0, n ) (or both at once). The natural number n
1400-407: Is one of some powers of 2 since computers store data in a binary format, the magnitude can be understood in terms of the amount of computer memory needed to store that value. Other orders of magnitude may be calculated using bases other than integers. In the field of astronomy , the nighttime brightnesses of celestial bodies are ranked by "magnitudes" in which each increasing level is brighter by
1456-440: Is one order of magnitude between 2 and 20, and two orders of magnitude between 2 and 200. Each division or multiplication by 10 is called an order of magnitude. This phrasing helps quickly express the difference in scale between 2 and 2,000,000: they differ by 6 orders of magnitude. Examples of numbers of different magnitudes can be found at Orders of magnitude (numbers) . Below are examples of different methods of partitioning
1512-488: Is the numbers 1 000 000 000 000 etc. SI units in the table at right are used together with SI prefixes , which were devised with mainly base 1000 magnitudes in mind. The IEC standard prefixes with base 1024 were invented for use in electronic technology. Integer An integer is the number zero ( 0 ), a positive natural number (1, 2, 3, . . .), or the negation of a positive natural number ( −1 , −2, −3, . . .). The negations or additive inverses of
1568-508: Is used to denote either the set of integers modulo p (i.e., the set of congruence classes of integers), or the set of p -adic integers . The whole numbers were synonymous with the integers up until the early 1950s. In the late 1950s, as part of the New Math movement, American elementary school teachers began teaching that whole numbers referred to the natural numbers , excluding negative numbers, while integer included
1624-523: The Latin integer meaning "whole" or (literally) "untouched", from in ("not") plus tangere ("to touch"). " Entire " derives from the same origin via the French word entier , which means both entire and integer . Historically the term was used for a number that was a multiple of 1, or to the whole part of a mixed number . Only positive integers were considered, making the term synonymous with
1680-417: The base of the logarithm and the representative of values of magnitude one. Logarithmic distributions are common in nature and considering the order of magnitude of values sampled from such a distribution can be more intuitive. When the reference value is 10, the order of magnitude can be understood as the number of digits minus one in the base-10 representation of the value. Similarly, if the reference value
1736-408: The integer part of the logarithm, obtained by truncation . For example, the number 4 000 000 has a logarithm (in base 10) of 6.602; its order of magnitude is 6. When truncating, a number of this order of magnitude is between 10 and 10 . In a similar example, with the phrase "seven-figure income", the order of magnitude is the number of figures minus one, so it is very easily determined without
Orders of magnitude (mass) - Misplaced Pages Continue
1792-443: The natural numbers . The definition of integer expanded over time to include negative numbers as their usefulness was recognized. For example Leonhard Euler in his 1765 Elements of Algebra defined integers to include both positive and negative numbers. The phrase the set of the integers was not used before the end of the 19th century, when Georg Cantor introduced the concept of infinite sets and set theory . The use of
1848-426: The ordered pairs ( 1 , n ) {\displaystyle (1,n)} with the mapping ψ = n ↦ ( 1 , n ) {\displaystyle \psi =n\mapsto (1,n)} . Finally let 0 be some object not in P {\displaystyle P} or P − {\displaystyle P^{-}} , for example the ordered pair (0,0). Then
1904-399: The effect of lowering the values of b {\displaystyle b} slightly: Orders of magnitude are used to make approximate comparisons. If numbers differ by one order of magnitude, x is about ten times different in quantity than y . If values differ by two orders of magnitude, they differ by a factor of about 100. Two numbers of the same order of magnitude have roughly
1960-407: The embedding mentioned above), this convention creates no ambiguity. This notation recovers the familiar representation of the integers as {..., −2, −1, 0, 1, 2, ...} . Some examples are: In theoretical computer science, other approaches for the construction of integers are used by automated theorem provers and term rewrite engines . Integers are represented as algebraic terms built using
2016-438: The existence of photons with arbitrarily low energies. Consequently, there can only ever be an experimental upper bound on the mass of a supposedly massless particle; in the case of the photon, this confirmed upper bound is of the order of 3 × 10 eV/ c = 10 kg . Order of magnitude Two numbers are "within an order of magnitude" of each other if their ratio is between 1/10 and 10. In other words,
2072-1179: The integers are defined to be the union P ∪ P − ∪ { 0 } {\displaystyle P\cup P^{-}\cup \{0\}} . The traditional arithmetic operations can then be defined on the integers in a piecewise fashion, for each of positive numbers, negative numbers, and zero. For example negation is defined as follows: − x = { ψ ( x ) , if x ∈ P ψ − 1 ( x ) , if x ∈ P − 0 , if x = 0 {\displaystyle -x={\begin{cases}\psi (x),&{\text{if }}x\in P\\\psi ^{-1}(x),&{\text{if }}x\in P^{-}\\0,&{\text{if }}x=0\end{cases}}} The traditional style of definition leads to many different cases (each arithmetic operation needs to be defined on each combination of types of integer) and makes it tedious to prove that integers obey
2128-458: The integers are not (since the result can be a fraction when the exponent is negative). The following table lists some of the basic properties of addition and multiplication for any integers a , b , and c : The first five properties listed above for addition say that Z {\displaystyle \mathbb {Z} } , under addition, is an abelian group . It is also a cyclic group , since every non-zero integer can be written as
2184-448: The integers as a subring is the field of rational numbers . The process of constructing the rationals from the integers can be mimicked to form the field of fractions of any integral domain. And back, starting from an algebraic number field (an extension of rational numbers), its ring of integers can be extracted, which includes Z {\displaystyle \mathbb {Z} } as its subring . Although ordinary division
2240-447: The integers into this ring. This universal property , namely to be an initial object in the category of rings , characterizes the ring Z {\displaystyle \mathbb {Z} } . Z {\displaystyle \mathbb {Z} } is not closed under division , since the quotient of two integers (e.g., 1 divided by 2) need not be an integer. Although the natural numbers are closed under exponentiation ,
2296-510: The letter Z to denote the set of integers comes from the German word Zahlen ("numbers") and has been attributed to David Hilbert . The earliest known use of the notation in a textbook occurs in Algèbre written by the collective Nicolas Bourbaki , dating to 1947. The notation was not adopted immediately. For example, another textbook used the letter J, and a 1960 paper used Z to denote
Orders of magnitude (mass) - Misplaced Pages Continue
2352-422: The mass equivalent to the energy represented by an electronvolt (eV). At the atomic level, chemists use the mass of one-twelfth of a carbon-12 atom (the dalton ). Astronomers use the mass of the sun ( M ☉ ). Unlike other physical quantities, mass–energy does not have an a priori expected minimal quantity, or an observed basic quantum as in the case of electric charge . Planck's law allows for
2408-437: The negative numbers. The whole numbers remain ambiguous to the present day. Ring homomorphisms Algebraic structures Related structures Algebraic number theory Noncommutative algebraic geometry Free algebra Clifford algebra Like the natural numbers , Z {\displaystyle \mathbb {Z} } is closed under the operations of addition and multiplication , that is,
2464-544: The non-negative integers. But by 1961, Z was generally used by modern algebra texts to denote the positive and negative integers. The symbol Z {\displaystyle \mathbb {Z} } is often annotated to denote various sets, with varying usage amongst different authors: Z + {\displaystyle \mathbb {Z} ^{+}} , Z + {\displaystyle \mathbb {Z} _{+}} , or Z > {\displaystyle \mathbb {Z} ^{>}} for
2520-400: The order of magnitude is included in the number name in this example, because bi- means 2, tri- means 3, etc. (these make sense in the long scale only), and the suffix -illion tells that the base is 1 000 000 . But the number names billion, trillion themselves (here with other meaning than in the first chapter) are not names of the orders of magnitudes, they are names of "magnitudes", that
2576-477: The order of magnitude of the number. The order of magnitude can be any integer . The table below enumerates the order of magnitude of some numbers using this definition: The geometric mean of 10 b − 1 / 2 {\displaystyle 10^{b-1/2}} and 10 b + 1 / 2 {\displaystyle 10^{b+1/2}} is 10 b {\displaystyle 10^{b}} , meaning that
2632-702: The positive integers, Z 0 + {\displaystyle \mathbb {Z} ^{0+}} or Z ≥ {\displaystyle \mathbb {Z} ^{\geq }} for non-negative integers, and Z ≠ {\displaystyle \mathbb {Z} ^{\neq }} for non-zero integers. Some authors use Z ∗ {\displaystyle \mathbb {Z} ^{*}} for non-zero integers, while others use it for non-negative integers, or for {–1,1} (the group of units of Z {\displaystyle \mathbb {Z} } ). Additionally, Z p {\displaystyle \mathbb {Z} _{p}}
2688-405: The positive natural numbers are referred to as negative integers . The set of all integers is often denoted by the boldface Z or blackboard bold Z {\displaystyle \mathbb {Z} } . The set of natural numbers N {\displaystyle \mathbb {N} } is a subset of Z {\displaystyle \mathbb {Z} } , which in turn
2744-727: The presence or absence of natural numbers as arguments of some of these operations, and the fact that these operations are free constructors or not, i.e., that the same integer can be represented using only one or many algebraic terms. The technique for the construction of integers presented in the previous section corresponds to the particular case where there is a single basic operation pair ( x , y ) {\displaystyle (x,y)} that takes as arguments two natural numbers x {\displaystyle x} and y {\displaystyle y} , and returns an integer (equal to x − y {\displaystyle x-y} ). This operation
2800-412: The products of primes in an essentially unique way. This is the fundamental theorem of arithmetic . Z {\displaystyle \mathbb {Z} } is a totally ordered set without upper or lower bound . The ordering of Z {\displaystyle \mathbb {Z} } is given by: :... −3 < −2 < −1 < 0 < 1 < 2 < 3 < ... . An integer is positive if it
2856-416: The real numbers into specific "orders of magnitude" for various purposes. There is not one single accepted way of doing this, and different partitions may be easier to compute but less useful for approximation, or better for approximation but more difficult to compute. Generally, the order of magnitude of a number is the smallest power of 10 used to represent that number. To work out the order of magnitude of
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#17327758024242912-417: The same scale: the larger value is less than ten times the smaller value. The growing amounts of Internet data have led to addition of new SI prefixes over time, most recently in 2022. The order of magnitude of a number is, intuitively speaking, the number of powers of 10 contained in the number. More precisely, the order of magnitude of a number can be defined in terms of the common logarithm , usually as
2968-404: The sum and product of any two integers is an integer. However, with the inclusion of the negative natural numbers (and importantly, 0 ), Z {\displaystyle \mathbb {Z} } , unlike the natural numbers, is also closed under subtraction . The integers form a ring which is the most basic one, in the following sense: for any ring, there is a unique ring homomorphism from
3024-422: The table) means that the commutative ring Z {\displaystyle \mathbb {Z} } is an integral domain . The lack of multiplicative inverses, which is equivalent to the fact that Z {\displaystyle \mathbb {Z} } is not closed under division, means that Z {\displaystyle \mathbb {Z} } is not a field . The smallest field containing
3080-482: The two numbers are within about a factor of 10 of each other. For example, 1 and 1.02 are within an order of magnitude. So are 1 and 2, 1 and 9, or 1 and 0.2. However, 1 and 15 are not within an order of magnitude, since their ratio is 15/1 = 15 > 10. The reciprocal ratio, 1/15, is less than 0.1, so the same result is obtained. Differences in order of magnitude can be measured on a base-10 logarithmic scale in " decades " (i.e., factors of ten). For example, there
3136-416: The various laws of arithmetic. In modern set-theoretic mathematics, a more abstract construction allowing one to define arithmetical operations without any case distinction is often used instead. The integers can thus be formally constructed as the equivalence classes of ordered pairs of natural numbers ( a , b ) . The intuition is that ( a , b ) stands for the result of subtracting b from
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