A rational number is a real number that can be expressed as a fraction or ratio of two integers where the denominator is not zero. Whole numbers, finite decimals and repeating decimals are rational.
According to Math Is Fun defines a rational number as a number that is in the form p/q where p and q are integers, but q does not equal to zero. Whole numbers are rational because for any whole number "p," it can be represented as the ratio p/1.
Examples of numbers that are irrational include the square root of 2 and the constant pi, approximated by 3.14. Decimals with an infinite expansion that do not repeat are considered irrational. According to Wolfram Math World, there are far fewer rational numbers on the real number line than there are irrational numbers.