Unitary Method of Solution (F)

The Unitary Method sounds like it might be complicated but it’s not! It’s a very useful way to solve problems involving ratio and proportion, so once you’ve mastered the technique in this GCSE Maths quiz have a go at the Ratio and Proportion quiz too!

The method involves scaling down one of the variables to a single unit, i.e. 1. Once we know the value of 1 unit, the value of multiple units can be found by multiplying. This will make more sense when it is explained using an example. If 12 tins of paint weigh 30kg, how much will 5 tins weigh? The first step in solving this is to find what ONE tin weighs. This will be 30/12 so 2.5kg. Scaling this back up for 5 tins gives 5 * 2.5 = 12.5kg.

The unitary method is also useful for working out which deal will give better value for money.