number

Also known as numbers

thumb|Set inclusions between the [[natural numbers ]]

AI overview

A number is a mathematical concept used to represent quantity, order, or measurement in a way that allows us to count, compare, and perform calculations. Numbers matter because they form the foundation for mathematics, science, commerce, and countless everyday activities where we need to quantify or organize things.

AI-generated from the Wikipedia summary — may contain errors.

~46 min read

Encyclopedic overview

40 sections

Contents

History
First use of numbers
Numerals
Zero
Negative numbers
Rational numbers
Real numbers and irrational numbers
Transcendental numbers and reals
Infinity and infinitesimals
Complex numbers
Prime numbers
Cultural and symbolic significance
Main classification
Natural numbers
Integers
Rational numbers
Real numbers
Repeating decimal
Irrational numbers
Set theory
Complex numbers
Subclasses of the integers
Even and odd numbers
Prime numbers
Other classes of integers
Subclasses of the complex numbers
Algebraic, irrational and transcendental numbers
Periods and exponential periods
Constructible numbers
Computable numbers
Extensions of the concept
''p''-adic numbers
Hypercomplex numbers
Transfinite numbers
Nonstandard numbers
See also
Notes
References
Further reading
External links

thumb|Set inclusions between the [[natural numbers ]]

A number is a mathematical object used to count, measure, and label. The most basic examples are the natural numbers: 1, 2, 3, 4, 5, and so forth. Individual numbers can be represented in spoken or written language with number words, or with dedicated symbols called numerals; for example, "eleven" is a number word and "11" is the corresponding numeral. As only a limited list of symbols can be memorized, a numeral system is used to represent any number in an organized way. The most common representation is the Hindu–Arabic numeral system, a decimal system which can display any non-negative integer using a combination of ten Arabic numeral symbols called digits. Numerals can be used for counting (as with cardinal number of a collection or set), for labelling (as with telephone numbers), for ordering (as with serial numbers), and for codes (as with ISBNs). In common usage, however, a numeral is not clearly distinguished from the number that it represents.

Excerpted from Wikipedia’s “number” article, available under the CC BY-SA 4.0 licence.