How to simplify fractions?

Answer 1

To simplify a fraction, you need to divide (cancel out) any common factors of the numerator and denominator. For example,

45/42 = (9*5)/(3*14) = (3*5)/(14) = 15/14.

A fast strategy for doing this: memorize divisibility rules:

For example, a number is divisible by 3 if the sum of its digits are divisible by 3 (ie: 4+5 = 9 = 3*3 and 4+2 = 6 = 3*2). There are other rules you should practice as you study.