If two things are proportional then the ratio of part to whole is maintained and the multiplicative relationship between parts is also maintained.

Checking and securing understanding of percentage increase

Maths

The ratio unit will cover comparing fractions, percentages and ratios and being able to move fluently between them. This unit ensures pupils have had the opportunity to work with finding the percentage of an amount and the opportunity to calculate interest.

In the prior unit, pupils developed the skills to calculate a given percentage of an amount. In this unit, these skills are extended to performing simple and compound interest calculations.

Percentages

A mathematician celebrates her shares increasing by 6.5%. They are now worth £426.00. How much did she originally invest?

If a number increases by 12% and is now 588, what was it originally? 

If a number increases by 26% and is now 77, what was it originally to 1 d.p.? 

Starter Quiz