percentage word problems answer to example 3

Tom planned to make 25 spare parts but actually made 20. what is the percentage of decrease?

The amount of decrease: 25-20=5

Ask yourself this question: decrease from “what”? the answer to “what” is “25” so 25 is the amount in 1

the 3 elements:

the amount in 1:25

the fraction: percentage of decrease?

the amount in the fraction: the amount of decrease, 5

the fraction= percentage of decrease= the amount in a fraction ÷ the amount in 1= 5÷25=20%