Number

A number is a mathematical object used to count, measure, and label. The original examples are the natural numbers 1, 2, 3, and so forth. 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 (as with telephone numbers), for ordering (as with serial numbers), and for codes (as with ISBNs). In common usage, number may refer to a symbol, a word, or a mathematical abstraction.

In mathematics, the notion of number has been extended over the centuries to include 0, negative numbers, rational numbers, r A number is a mathematical object used to count, measure, and label. The original examples are the natural numbers 1, 2, 3, and so forth. 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 (as with telephone numbers), for ordering (as with serial numbers), and for codes (as with ISBNs). In common usage, number may refer to a symbol, a word, or a mathematical abstraction.

In mathematics, the notion of number has been extended over the centuries to include 0, negative numbers, rational numbers, real numbers such as √2 and π, and complex numbers, which extend the real numbers by adding a square root of −1. Calculations with numbers are done with arithmetical operations, the most familiar being addition, subtraction, multiplication, division, and exponentiation. Their study or usage is called arithmetic. The same term may also refer to number theory, the study of the properties of numbers.

Besides their practical uses, numbers have cultural significance throughout the world. For example, in Western society, the number 13 is regarded as unlucky, and "a million" may signify "a lot." Though it is now regarded as pseudoscience, numerology, the belief in a mystical significance of numbers, permeated ancient and medieval thought. Numerology heavily influenced the development of Greek mathematics, stimulating the investigation of many problems in number theory which are still of interest today.

During the 19th century, mathematicians began to develop many different abstractions which share certain properties of numbers and may be seen as extending the concept. Among the first were the hypercomplex numbers, which consist of various extensions or modifications of the complex number system. Today, number systems are considered important special examples of much more general categories such as rings and fields, and the application of the term "number" is a matter of convention, without fundamental significance. ...more

Most Read This Week Tagged "Number"

Pete the Cat and the Missing Cupcakes: A Groovy Mystery Adventure with Pete and the Case of the Missing Cupcakes

Pete the Cat and His Four Groovy Buttons

Naked Statistics: Stripping the Dread from the Data

More most read this week tagged "number"...

Number Books

More number books...

Lists

Killers of the Flower Moon by David Grann

Non-Fiction read in 2017

481 books — 87 voters

When Was That? Dates in Titles

667 books — 112 voters

We Were Eight Years in Power by Ta-Nehisi Coates

Eight Is Great

445 books — 36 voters

The Ninth

283 books — 31 voters

The Six Wives of Henry VIII by Alison Weir

The Autobiography of Henry VIII by Margaret George

Young and Damned and Fair by Gareth Russell

Sesam nieuwe/geïllustreerde wereldgeschiedenis. Deel 16 by Carl Grimberg

Roman Numerals

105 books — 9 voters

Slaughterhouse-Five by Kurt Vonnegut Jr.

Books with Numbers in the Title

1,922 books — 208 voters

Featured News & Interviews

New Voices Alert! 51 New & Upcoming Debut Novels

Read »

Quotes Tagged “Number”

“ There are infinite numbers between 0 and 1. There's .1 and .12 and .112 and an infinite collection of others. Of course, there is a bigger infinite set of numbers between 0 and 2, or between 0 and a million. Some infinities are bigger than other infinities... I cannot tell you how grateful I am for our little infinity. You gave me forever within the numbered days, and I'm grateful. ...more ”
― John Green, The Fault in Our Stars

91 likes

“ However cozy things seemed, the facts of life were the same. You couldn't escape death: It would get us all in the end. ...more ”
― Rachel Ward, Numbers

17 likes

More quotes...