irrational number

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noun Mathematics.

a number that cannot be exactly expressed as a ratio of two integers.

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Origin of irrational number

First recorded in 1545–55

Words nearby irrational number

irradicable, irrational, irrationalism, irrationality, irrationalize, irrational number, Irrawaddy, irreal, irrebuttable, irreclaimable, irreconcilable

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use irrational number in a sentence

This is because there are way more irrational numbers than rational numbers.
The Coach Who Led the U.S. Math Team Back to the Top|Max G. Levy|February 16, 2021|Quanta Magazine
So what’s kind of funny is that you didn’t provide me a number — an irrational number — that is actually the most common kind of number there is.
The Coach Who Led the U.S. Math Team Back to the Top|Max G. Levy|February 16, 2021|Quanta Magazine
“Our members continue to face a number of challenges,” she said.
The Republican War on Kale|Patricia Murphy|January 7, 2015|DAILY BEAST
The number of dissenters though is unprecedented in the modern era.
Democrats Accidentally Save Boehner From Republican Coup|Ben Jacobs, Jackie Kucinich|January 6, 2015|DAILY BEAST

The Samaritan guidelines are written around the assumption that suicide is a purely irrational act, an act spurred by illness.
Cover-Ups and Concern Trolls: Actually, It's About Ethics in Suicide Journalism|Arthur Chu|January 3, 2015|DAILY BEAST
Starting under Theodore Roosevelt and Howard Taft, embassies headed by career diplomats increased in number.
U.S. Embassies Have Always Been for Sale|William O’Connor|January 2, 2015|DAILY BEAST
The number of diplomats was pitiful (45 appointees in 1860), as was the amount of money allocated to them.
U.S. Embassies Have Always Been for Sale|William O’Connor|January 2, 2015|DAILY BEAST
The country is well inhabited, for it contains fifty-one cities, near a hundred walled towns, and a great number of villages.
Gulliver's Travels|Jonathan Swift
We had six field-pieces, but we only took four, harnessed wit twice the usual number of horses.
Blackwood's Edinburgh Magazine, No. CCCXXXIX. January, 1844. Vol. LV.|Various
There are a number of bacilli, called acid-fast bacilli, which stain in the same way as the tubercle bacillus.
A Manual of Clinical Diagnosis|James Campbell Todd
Five of the number had studied with Liszt before, and the young men are artists already before the public.
Music-Study in Germany|Amy Fay
I do not think the average number of passengers on a corresponding route in our country could be so few as twenty.
Glances at Europe|Horace Greeley

British Dictionary definitions for irrational number

irrational number

noun

any real number that cannot be expressed as the ratio of two integers, such as π

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for irrational number

irrational number

[ ĭ-răsh′ə-nəl ]

A number that cannot be expressed as a ratio between two integers and is not an imaginary number. If written in decimal notation, an irrational number would have an infinite number of digits to the right of the decimal point, without repetition. Pi and the square root of 2 (√2) are irrational numbers.

Cultural definitions for irrational number

irrational number

A number that cannot be expressed as the ratio of two whole numbers.

notes for irrational number

The square roots of most whole numbers are irrational numbers.