rational numbers

Rational numbers are numbers that can be written as a fraction. The top number of the fraction is called the numerator and the bottom number is called the denominator. To be a rational number, the denominator cannot be 0. For example, 4/5 is a rational number, but 4/0 is not. Rational numbers can also be written with decimals. For example, 3/4 can also be written as 0.75.