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.

Read more about Number: Classification of Numbers, Numerals

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

**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 ...

**number**)

... This article discusses the

**number**thirty-eight ... uses of 38, see 38 (disambiguation) ← 39 ... → 38 ← 39 ... → List of

**numbers**— Integers 90 ... → Cardinal thirty-eight Ordinal 38th (thirty ...

*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 ...

**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) ... of 392 + 1 = 1522 is 761, which is obviously more than 39 twice, 39 is a Størmer

**number**...

**number**) - In Other Fields

... 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 around ... History The

**number**of signers to the United States Constitution, out of 55 members of the Philadelphia Convention delegates The traditional

**number**of times ... Japanese Internet chat 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 ...

### Famous quotes containing the word number:

“Strange goings on! Jones did it slowly, deliberately, in the bathroom, with a knife, at midnight. What he did was butter a piece of toast. We are too familiar with the language of action to notice at first an anomaly: the ‘it’ of ‘Jones did it slowly, deliberately,...’ seems to refer to some entity, presumably an action, that is then characterized in a *number* of ways.”

—Donald Davidson (b. 1917)

“In proportion as our inward life fails, we go more constantly and desperately to the post office. You may depend on it, that the poor fellow who walks away with the greatest *number* of letters, proud of his extensive correspondence, has not heard from himself this long while.”

—Henry David Thoreau (1817–1862)

“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)