Year 9 Percentage Increase and Decrease Worksheet — Level 1 — Practice Set 4 — Answers
Answer sheet with worked solutions for the Year 9 percentages worksheet.
Success TutoringWorksheetsAnswer sheetYear 9 · Mathematics · PercentagesYear 9 Percentage Increase and Decrease Worksheet — Level 1 — Practice Set 4 — Answers
Percentage change = change ÷ original amount × 100. Always divide by the original amount.
1.A price changes from $20 to $15. Find the percentage decrease.
Answer: 25%
- Change = 20 − 15 = 5
- 5 ÷ 20 × 100 = 25%
2.A price changes from $280 to $140. Find the percentage decrease.
Answer: 50%
- Change = 280 − 140 = 140
- 140 ÷ 280 × 100 = 50%
3.A price changes from $190 to $171. Find the percentage decrease.
Answer: 10%
- Change = 190 − 171 = 19
- 19 ÷ 190 × 100 = 10%
4.A price changes from $370 to $407. Find the percentage increase.
Answer: 10%
- Change = 407 − 370 = 37
- 37 ÷ 370 × 100 = 10%
5.A price changes from $80 to $72. Find the percentage decrease.
Answer: 10%
- Change = 80 − 72 = 8
- 8 ÷ 80 × 100 = 10%
6.A price changes from $200 to $180. Find the percentage decrease.
Answer: 10%
- Change = 200 − 180 = 20
- 20 ÷ 200 × 100 = 10%
7.A price changes from $320 to $240. Find the percentage decrease.
Answer: 25%
- Change = 320 − 240 = 80
- 80 ÷ 320 × 100 = 25%
8.A price changes from $30 to $24. Find the percentage decrease.
Answer: 20%
- Change = 30 − 24 = 6
- 6 ÷ 30 × 100 = 20%
9.A price changes from $60 to $48. Find the percentage decrease.
Answer: 20%
- Change = 60 − 48 = 12
- 12 ÷ 60 × 100 = 20%
10.A price changes from $210 to $315. Find the percentage increase.
Answer: 50%
- Change = 315 − 210 = 105
- 105 ÷ 210 × 100 = 50%
Marking tips
- Give credit for correct method even when the final answer slips — the working shows where the thinking went right.
- For open-ended tasks, use the success criteria as a checklist rather than looking for one "right" answer.
- Celebrate what went well first, then pick one thing to work on next.