real number

American  

[ree-uhl, reel] / ˈri əl, ril /

noun

Mathematics.

1. a rational number or the limit of a sequence of rational numbers, as opposed to a complex number.

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real number British  

noun

1. a number expressible as a limit of rational numbers See number

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real number Scientific  

/ rē′əl /

1. A number that can be written as a terminating or nonterminating decimal; a rational or irrational number. The numbers 2, −12.5, 3/7, and pi (π) are all real numbers.

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Etymology

Origin of real number

First recorded in 1905–10

Example Sentences

The real number is higher, as some of the most troubled mortgages are taken out of the MBS pool of loans.

From The Wall Street Journal • May 3, 2026

Most advocates believe the real number is at least 5,000.

From Slate • Mar. 25, 2026

Tripoli Mayor Abdel Hamid Karimeh told AFP that at least 600 buildings needed "direct intervention to reinforce them", but warned that the real number could be much higher.

From Barron's • Feb. 9, 2026

The real number of people killed and detained is believed to be significantly higher, but the lack of access means the figures cannot be independently verified.

From BBC • Jan. 18, 2026

Imagine that we’ve already got a perfect seating plan for the real numbers: every real number has a seat, and every seat is filled.

From "Zero: The Biography of a Dangerous Idea" by Charles Seife