Rational numbers are the type of numbers that can be written in fraction forms (1/b where a and b are integers and b ≠ 0). Rational numbers also include decimals that are repetitive (0.313131313131) and decimals that end (0.25).
The opposite are irrational numbers that cannot be written in fraction forms and that include decimals that do not end or repeat (0.249654296432926....).
It is good to know a fraction with denomination equal to zero will give an undefined value.
