real number

quantity along a continuous line

AI overview

A real number is any quantity that can be placed on a continuous line, including whole numbers, fractions, and numbers like pi that can't be expressed as simple fractions. Real numbers matter because they allow us to measure and describe nearly everything in the physical world, from distances and temperatures to speeds and amounts.

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

Wikidata facts

Subclass of: number
Part of: real line
Image: Number-line.svg

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Commons category: Real numbers
different from: set of real numbers
opposite of: imaginary number
topic's main category: Category:Real numbers
on focus list of Wikimedia project: Wikipedia:Vital articles/Level/4
maintained by WikiProject: WikiProject Mathematics
Stack Exchange tag: math.stackexchange.com/tags/real-numbers

Sources (5)

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Encyclopedic overview

Real numbers can be thought of as all points on a number line.

In mathematics, a real number is a number that can be used to measure a continuous one-dimensional quantity such as a length, duration or temperature. Here, continuous means that pairs of values can have arbitrarily small differences. Every real number can be almost uniquely represented by an infinite decimal expansion.

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