6.4 Simple and compound interest — Practise with help
Try each question before opening a hint. Reveal the full working to check your method.
Warm-up: remember
- Write the multiplier for 6% growth.
- Work out 10% of £400.
Check your answers
- 1.06. 2. 40.
Practise with help
1. Find the simple interest on £300 at 5% for 4 years.
Hint
Find one year’s interest first.
Full working
£300 × 0.05 × 4 = £60.
2. Find the compound amount for £400 at 10% for 2 years.
Hint
Apply 1.10 twice.
Full working
£400 × 1.10² = £484.
3. Compare simple and compound totals for £1000 at 2% for 3 years.
Hint
Calculate both totals.
Full working
Simple: £1,060. Compound: £1,061.21.
Progress check: revisit your savings estimate. What calculation would make it exact?