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

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

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

“Many people experience fraud and never complain to anyone about it. Only 4.8 percent of people ever complain to a government entity, so the real number is much, much higher,” she said.

From Slate • Aug. 4, 2025

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

From Salon • Feb. 2, 2025

That means we can make a list of seats, showing a seat's number along with the real number that is sitting in it.

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