# 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":

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, 124, 248 and 496, (t ...
39 (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 the ... 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 ... 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 ...
38 (number)
... This article discusses the number thirty-eight. 38 ← 39 ... → List of numbers — Integers 90 ... → Cardinal thirty-eight Ordinal 38th (thirty-eighth) Factorization ...
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 ...
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). 392 + 1 = 1522 is 761, which is obviously more than 39 twice, 39 is a Størmer number ...

### Famous quotes containing the word number:

I who have been involved with all styles of painting can assure you that the only things that fluctuate are the waves of fashion which carry the snobs and speculators; the number of true connoisseurs remains more or less the same.
Pablo Picasso (1881–1973)

I can’t quite define my aversion to asking questions of strangers. From snatches of family battles which I have heard drifting up from railway stations and street corners, I gather that there are a great many men who share my dislike for it, as well as an equal number of women who ... believe it to be the solution to most of this world’s problems.
Robert Benchley (1889–1945)

In this world, which is so plainly the antechamber of another, there are no happy men. The true division of humanity is between those who live in light and those who live in darkness. Our aim must be to diminish the number of the latter and increase the number of the former. That is why we demand education and knowledge.
Victor Hugo (1802–1885)