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**)

... This article discusses the

**number**thirty-eight. 39 ... → List of

**numbers**— Integers 90 ... → Cardinal thirty-eight Ordinal 38th (thirty-eighth) Factorization Divisors 1, 2, 19, 38 Roman numeral ...

**number**) - In Other Fields

... 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 around the world ... 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 ... 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

**number**39 is considered unlucky, due to the ...

**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, 124 ...

*natural Logarithm*

... But mathematically, the

**number**10 is not particularly significant ... 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) ... is 761, which is obviously more than 39 twice, 39 is a Størmer

**number**...

### Famous quotes containing the word number:

“Envy has blackened every page of his history.... The future, in its justice, will *number* him among those men whom passions and an excess of activity have condemned to unhappiness, through the gift of genius.”

—Eugène Delacroix (1798–1863)

“While I do not suggest that humanity will ever be able to dispense with its martyrs, I cannot avoid the suspicion that with a little more thought and a little less belief their *number* may be substantially reduced.”

—J.B.S. (John Burdon Sanderson)

“Of all reformers Mr. Sentiment is the most powerful. It is incredible the *number* of evil practices he has put down: it is to be feared he will soon lack subjects, and that when he has made the working classes comfortable, and got bitter beer into proper-sized pint bottles, there will be nothing left for him to do.”

—Anthony Trollope (1815–1882)