Starter quiz
- Write 24 as a percentage of 400
- '6' ✓
- Write 18 as a percentage of 150
- '12%' ✓
- Find 24% of 70
- '16.8' ✓
- Find 60% of 90
- '54' ✓
- Write 65 as a percentage of 500
- '13' ✓
- Find 216% of 856
- '1848.96' ✓
Exit quiz
- Increase 250 by 5%
- '262.5' ✓
- Increase 250 by 6.4%
- '266' ✓
- Increase 500 by 0.71%
- '503.55' ✓
- A mathematician celebrates her shares increasing by 6.5%. They are now worth £426.00. How much did she originally invest?
- '400' ✓
- If a number increases by 12% and is now 588, what was it originally?
- '525' ✓
- If a number increases by 26% and is now 77, what was it originally to 1 d.p.?
- '61.1' ✓
Worksheet
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Presentation
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Video
Lesson Details
Key learning points
- In all of these representations a single multiplier can be used to find a percentage increase.
- Representation can help when you are not using a calculator.
- A multiplier is significantly faster when using a calculator.
- To increase, you are going above the original amount.
Common misconception
A single digit percentage is incorrectly worked out by dividing by 10 and not 100 e.g 3% = 0.3. This error continues when increasing amounts e.g increase 40 by 3% has a multiplier of 1.3
Remind pupils that to covert a percentage into a decimal we divide by 100. This applies with increase too e.g 120% has a multiplier of 1.2
Keywords
Proportion - If two things are proportional then the ratio of part to whole is maintained and the multiplicative relationship between parts is also maintained.
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