Number

Rational number

A number you can write as a fraction p/q where p and q are integers and q ≠ 0.

Definition

Rational numbers include every integer, every terminating decimal, and every recurring decimal. The set is denoted ℚ.

Example

½, −0.75, 3, 0.333... are all rational. π and √2 are not.

Related terms

Irrational number

A number that cannot be written as a fraction of two integers — its decimal goes on forever without repeating.

Integer

A whole number — positive, negative or zero. No fractions or decimals.

Surd

An irrational root that cannot be simplified to a rational number, e.g. √2, √15.

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