In mathematics, a rational number is a number that can be expressed as the quotient or fraction of two integers, where the denominator is not zero. Any fraction with non-zero denominators is a rational number. For example, 1.5 is a rational number because it can be expressed as 3/2, where 3 and 2 are both integers. Every whole number is a rational number because every whole number can be expressed as a fraction. The set of rational numbers includes integers, fractions, and terminating or repeating decimals. The term "rational" in reference to the set refers to the fact that a rational number represents a ratio of two integers.