A rational number is a number that can be written as a fraction or "ratio".
It includes the set of integers because all of them have a denominator of 1. A rational number can take on the form of [tex] \frac{a}{b} [/tex] where b ≠ 0. Terminating and repeating decimals are rational numbers because they too can be written as a ratio; for example, 0.3 = [tex] \frac{3}{10} [/tex] or 0.3333... = [tex] \frac{1}{3} [/tex].