Watch the animation for calculating percentage increase and decrease, and then consider the question below.

Why use this technique? Is it appropriate?

• We calculate percentage increase and decrease to show how much ‘increase’ or ‘decrease/loss’ there has been in a specific category over time.
• By working out the percentage change it is easier to compare the change in a category over time e.g. population change.
• Working out a percentage is much more understandable than looking at raw figures. It also means that data is more easily comparable.

Evaluate the strengths and limitations of calculating percentage change.

##### Limitations

Strengths of calculating percentage change:-

• When comparing the difference in change between categories, it is much easier to compare change as a percentage rather than raw figures, as the figures may be very different.
• By using a percentage it is easier to see how big or small changes are.

Weaknesses of calculating percentage change:–

• It can be quite a difficult calculation to work out as there are many steps.