This document defines and provides examples of rational and irrational numbers. Rational numbers can be written as a ratio of two integers and when expressed as decimals are either terminating or repeating. Irrational numbers cannot be expressed as ratios and their decimal representations are non-terminating and non-repeating. Examples of rational numbers include integers and fractions while irrational numbers include square roots of non-perfect squares and pi. Integers are a subset of rational numbers as they can be expressed as fractions with a denominator of 1.