# Number

A number is a mathematical object used to count, label, and measure. In mathematics, the definition of number has been extended over the years to include such numbers as zero, negative numbers, rational numbers, irrational numbers, and complex numbers.

Mathematical operations are certain procedures that take one or more numbers as input and produce a number as output. Unary operations take a single input number and produce a single output number. For example, the successor operation adds one to an integer, thus the successor of 4 is 5. Binary operations take two input numbers and produce a single output number. Examples of binary operations include addition, subtraction, multiplication, division, and exponentiation. The study of numerical operations is called arithmetic.

A notational symbol that represents a number is called a numeral. In addition to their use in counting and measuring, numerals are often used for labels (telephone numbers), for ordering (serial numbers), and for codes (e.g., ISBNs).

In common use, the word number can mean the abstract object, the symbol, or the word for the number.

### Other articles related to "number, numbers":

Natural Logarithm - Origin of The Term natural Logarithm
... But mathematically, the number 10 is not particularly significant ... the basis for many societies’ numbering systems—likely arises from humans’ typical number of fingers ... As an example, there are a number of simple series involving the natural logarithm ...
38 (number)
... This article discusses the number thirty-eight. 38, see 38 (disambiguation) ← 39 ... → 38 ← 39 ... → List of numbers — Integers 90 ... → Cardinal thirty-eigh ...
39 (number) - In Other Fields
39" does in fact fall in the thirty-ninth position The retired jersey number of former baseball player Roy Campanella The book series "The 39 Clues" revolves around 39 clues hidden ... History The number of signers to the United States Constitution, out of 55 members of the Philadelphia Convention delegates The traditional number of times citizens of Ancient Rome hit their slaves when ... slang for "thank you" when written with numbers (3=san 9=kyu) Pier 39 in San Francisco The number of the French department Jura In Afghanistan, the number 39 is considered ...
496 (number) - In Mathematics
496 is most notable for being a perfect number, and one of the earliest numbers to be recognized as such ... As a perfect number, it is tied to the Mersenne prime 31, 25 - 1, with 24 ( 25 - 1 ) yielding 496 ... Also related to its being a perfect number, 496 is a harmonic divisor number, since the number of proper divisors of 496 divided by the sum of the reciprocals of its divisors, 1, 2, 4, 8, 16, 31, 62 ...
39 (number) - In Mathematics
39 is the smallest natural number which has three partitions into three parts which all give the same product when multiplied {25, 8, 6}, {24, 10, 5}, {20, 15, 4} ... The thirteenth Perrin number is 39, which comes after 17, 22, 29 (it is the sum of the first two mentioned) ... obviously more than 39 twice, 39 is a Størmer number ...

### Famous quotes containing the word number:

The Oregon [matter] and the annexation of Texas are now all- important to the security and future peace and prosperity of our union, and I hope there are a sufficient number of pure American democrats to carry into effect the annexation of Texas and [extension of] our laws over Oregon. No temporizing policy or all is lost.
Andrew Jackson (1767–1845)

No Government can be long secure without a formidable Opposition. It reduces their supporters to that tractable number which can be managed by the joint influences of fruition and hope. It offers vengeance to the discontented, and distinction to the ambitious; and employs the energies of aspiring spirits, who otherwise may prove traitors in a division or assassins in a debate.
Benjamin Disraeli (1804–1881)

At thirty years a woman asks her lover to give her back the esteem she has forfeited for his sake; she lives only for him, her thoughts are full of his future, he must have a great career, she bids him make it glorious; she can obey, entreat, command, humble herself, or rise in pride; times without number she brings comfort when a young girl can only make moan.
Honoré De Balzac (1799–1850)