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rational number

American  

noun

Mathematics.
  1. a number that can be expressed exactly by a ratio of two integers.


rational number British  

noun

  1. any real number of the form a / b , where a and b are integers and b is not zero, as 7 or 7/3

"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

rational number Scientific  
  1. A number that can be expressed as an integer or a quotient of integers. For example, 2, −5, and 1/2 are rational numbers.


Etymology

Origin of rational number

First recorded in 1900–05

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

And the box “What Are Imaginary Numbers?” should have said that rational numbers include the integers, not that “rational numbers are the integers.”

From Scientific American

Even such bonkers-looking numbers, however, together with all the rational numbers, make up only a tiny fraction of the real numbers, or numbers that can appear along a number line.

From Scientific American

If the two new arrangements contained repeating patterns, the length of their translation vectors should have been related to each other—specifically, their ratio should have been a rational number.

From Scientific American

The conjecture predicts that the corresponding field will be “the smallest field that you get by taking sums, products and rational number multiples of these roots,” Arthur says.

From Scientific American

Poonen has worked to show that such a general method for finding solutions in rational numbers is impossible.

From Scientific American