BUTTERFLY METHOD

The butterfly method is widely used for calculating fractions. Let us learn the method with the steps below. Let's take the example 3/5 - 1/4

First, draw a butterfly on the fractions, as shown above. Notice, that each oval has two numbers. First multiply 3×4 and write its product (12) above 3/5. Next, multiply 5×1 and write its product above 1/4. Now you have got 12-5.

Subtract this and write 7 in the numerator for your answer. Finally, multiply both the denominators 5×4, which is 20, and write it in the denominator as your answer. Now you have your answer, which is 7/20.