Starter quiz
- If I increase £45 to £126, what is the percentage gain?
- '180%' ✓
- Find 52% of 800
- '416' ✓
- A data analyst celebrates his investment increasing by 14% which is now worth £1094.40. How much did he originally invest?
- '960' ✓
- Increase 11 by 15%
- '12.65' ✓
- If I decrease £48 to £12, what is the percentage loss?
- '75%' ✓
- If I increase £75 to £97.50, what is the percentage gain?
- '30' ✓
Exit quiz
- What is the amount of simple 1.3% interest earned on an investment of £400 over 6 years?
- £31.20 ✓
- £34.20
- £32.23
-
- What is the amount of simple 1.6% interest earned on an investment of £500 over 4 years?
- £32.78
- £32 ✓
- £32.50
-
- What is the amount of simple 2.8% interest earned on an investment of £638 over 10 years?
- £202.91
- £178.64 ✓
- £178.64 ✓
-
- What is the amount of compound 2.8% interest earned on an investment of £638 over 10 years?
- £202.91 ✓
- £178.64
- £178.64
-
- What is the amount of compound 4.9% interest earned on an investment of £230 over 8 years (to 2 d.p.)?
- '107.23' ✓
- What is the amount of compound 2.3% interest earned on an investment of £1000 over 20 years (to 2 d.p.)?
- '575.84' ✓
Worksheet
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Presentation
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Video
Lesson Details
Key learning points
- Calculators are very useful here as they can be programmed efficiently.
- This saves time and can reduce error.
- It is also quick to reverse the process to find the original amount.
- The use of a multiplier ensures greater efficiency.
Common misconception
A single digit percentage is incorrectly worked out by dividing by 10 and not 100 e.g 3% = 0.3, e.g. 0.54% = 0.054
Dividing the percentage by 100 gives the decimal equivalent i.e 0.54% = 0.0054
Keywords
Simple interest - Interest is money added to savings or loans. Simple interest is always calculated on the original amount
Compound interest - Compound interest is the interest calculated on the original amount and the interest accumulated over the previous period.
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