Lesson 3. Direct proportion

EXAMPLES:

5 doughnuts cost 80p. How much will 12 doughnuts cost?

Find the cost of 1 doughnut and then find the cost of 12.

5 doughnuts cost 80p

1 doughnuts cost 80 ÷ 5 =16p

12 doughnuts cost 16p × 12 = 192p = £1.92

Tasks to the lesson 3

• Test 1
• Test 2
• Test 3

Other lessons:

• Lesson 1. Patio
• Lesson 5. Sharing in a given ratio
• Lesson 6. Percentages
• Lesson 7. Percentage of a number
• Lesson 9. Percentage change
• Lesson 10. Compound interest-type problems
• Lesson 11. Tasks for a time