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

Youth unemployment officially stands around 15%, though many analysts believe the real number is higher.

From Barron's • Feb. 15, 2026

Those bites cause about 30,000 deaths annually in sub-Saharan Africa, though some estimates suggest the real number is much higher.

From BBC • Feb. 1, 2026

And civil rights groups widely agree that the real number of attacks was likely far higher, as many incidents went unreported by victims who feared drawing even more attention.

From Slate • Oct. 29, 2025

That’s the portion willing to admit it, at least – the real number could be far higher.

From Salon • Feb. 2, 2025

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