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

Zero in the Title - Fiction

355 books — 32 voters

When Was That? Dates in Titles

667 books — 112 voters

Slaughterhouse-Five by Kurt Vonnegut Jr.

Books with Numbers in the Title

1,914 books — 205 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

The Vacancy in Room 10 by Seraphina Nova Glass

The Haunting of Room 904 by Erika T. Wurth

The Book in Room 316 by ReShonda Tate Billingsley

Room Service?

127 books — 9 voters

The Very Hungry Caterpillar by Eric Carle

Counting Books

345 books — 63 voters

Featured News & Interviews

New Nonfiction to Read This Women's History Month

Read »

Quotes Tagged “Number”

“ . . . we come astonishingly close to the mystical beliefs of Pythagoras and his followers who attempted to submit all of life to the sovereignty of numbers. Many of our psychologists, sociologists, economists and other latter-day cabalists will have numbers to tell them the truth or they will have nothing. . . . We must remember that Galileo merely said that the language of nature is written in mathematics. He did not say that everything is. And even the truth about nature need not be expressed ...more ”
― Neil Postman, Amusing Ourselves to Death: Public Discourse in the Age of Show Business

16 likes

“ I got home from the FBi that day, put on my pajamas got a pint of Chunky Monkey, and watched 'The Notebook'. Five times. Everyone left me alone. I suspect they were a little afraid of me. I went up to my room and listened to Taylor Swift's 'White Horse' on replay, knowing she was the only person in the world who could relate. ...more ”
― Annabel Monaghan, A Girl Named Digit

32 likes

More quotes...