Variables are in proportion if they have a constant multiplicative relationship.

Finding the percentage change

Maths

In this unit, pupils develop the skills to calculate a given percentage of an amount. In the percentages unit, this is extended to performing simple and compound interest calculations. 

The multiplicative relationship is extended in this unit by considering percentages and the connections between multiplicative relationships and direct proportion. By building on a secure understanding of fractions and ratio, pupils can see their understanding of multiplicative relationships being extended.

Understanding multiplicative relationships: percentages and proportionality

__________ is the decimal equivalent of a percentage.

100% = 36 and 120% = 43.2. The percentage change is {{ }}%.

The cost of a laptop decreases from £450 to £360.  What is the percentage change?

Jun thinks of a number and decreases it by a percentage.  The number Jun thought of was 160 and his new number is 136.  Jun changed  160 by {{ }}%

Jacob’s score on a game increases from 3450 to 3726.  The percentage change in Jacob's score is {{ }}%.

A reduced sugar bar of chocolate contains 35 g of sugar.  The normal bar contains 15 g more of sugar.  The sugar has been reduced by {{}}%.

Which of the following words indicate an decrease?

Which of the following is the correct calculation for finding 5% of 300?

Match each question to the correct multiplier.

A t-shirt costs £13.50 in a sale offering a 25% discount.  The cost of the t-shirt before the discount was £{{ }}

The value of a motorbike depreciates by 12% each year.  It is now worth £6512. Last year the motorbike was worth £{{ }}.

Mr. Oak sells a vase for £72.  This gives him a 20% profit.  Mr. Oak originally purchased the vase for £{{ }}.

This lesson will soon be taken down.

Finding the percentage change

Lesson outcome