# 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.

#### More From encyclopedia.com

Imaginary Number , Imaginary number
An imaginary number is the square root of a negative real number. (The square root of a number is a second number that, when multipl… Numbers , numbers Numbers is the name of the fourth book of the Bible, relating the experiences of the Israelites in the wilderness after Moses led them out of… Arithmetic , Arithmetic is a branch of mathematics concerned with the numerical manipulation of numbers using the operations of addition , subtraction , multiplic… Real Numbers , A real number is any number which can be represented by a point on the number line. The numbers 3.5, 0.003, 2/3, π, and are all real numbers.
The rea… Whole Number , Numbers, Whole
The whole number set contains the counting numbers 1, 2, 3,… and the number 0. In mathematics, the whole number set is the most basic… Fibonacci Series , Fibonacci series A sequence of numbers in which each number is the sum of the two preceding numbers, e.g. 0,1,1,2,3,5,8,…
The Fibonacci numbers Fn ar…

#### You Might Also Like

#### NEARBY TERMS

**Irrational Number**