I'm doing geometry for credit advancement in Odysseyware. Brainly and Openstudy are saviors. Anyways. So, and irrational number can't be written as a fraction, but can be written as a decimal. An irrational number has endless non repeating number to the right of the decimal point. A rational number is a number that can be written in a ratio. Which in turn means it can be written as a fraction. Both number of the fraction (numerator and denominator) are whole numbers. Any whole number is a rational number. <span />