A rational number is a number which can be written as a ratio of two whole numbers (integers). For example 5 is a rational number since 5 can be written as ratio of 5 : 1 . 5 is also an integer. 2.5 is a rational number since it is a ratio of 5 : 2.
Any fraction that can not simplify to a whole number 0,1,2,3,... or the opposite of a whole number -1,-2, -3,... ANSWER The answer to your comment question is because you can not write it as a fraction...rational number