## Irrational Number

## Irrational Number

# Irrational Number

An irrational number is a number that cannot be expressed as a fraction, that is, cannot be written as the quotient of two whole numbers. As a decimal, an irrational number is shown by an infinitely long nonrepeating sequence of numbers. Examples of commonly used irrational numbers are π (*pi*, the ratio of circumference to diameter of a circle); e, base of the natural logarithms); and 2 (that number which multiplied by itself equals 2). There is an infinite number of irrational numbers.

*See also* e (number); Rational number.

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