Numbers that cannot be written as fractions where both the numerator and denominator are integers and the denominator is not zero. For example, and are irrational numbers. An irrational number can be represented by a nonterminating, nonrepeating decimal. For example, the decimal for , 3.141592653…, continues without a repeating pattern. The number 1.10100100010000… is irrational; there is a pattern in the decimal, but it does not repeat.