Year 3 Estimating Sums, Differences and Products Worksheet — Level 2 — Practice Set 3 — Answers
Answer sheet with worked solutions for the Year 3 place value worksheet.
Success TutoringWorksheetsAnswer sheetYear 3 · Mathematics · Place ValueYear 3 Estimating Sums, Differences and Products Worksheet — Level 2 — Practice Set 3 — Answers
Round each number first, then work out the estimate in your head.
1.Estimate 507 + 253 by rounding each number to the nearest 100.
Answer: 800
- 507 rounds to 500; 253 rounds to 300
- 500 + 300 = 800
The exact answer is 760, close to the estimate.
2.Estimate 84 × 9 by rounding 84 to the nearest 10.
Answer: 720
- 84 rounds to 80
- 80 × 9 = 720
The exact answer is 756.
3.Estimate 170 + 824 by rounding each number to the nearest 100.
Answer: 1,000
- 170 rounds to 200; 824 rounds to 800
- 200 + 800 = 1,000
The exact answer is 994, close to the estimate.
4.Estimate 31 × 3 by rounding 31 to the nearest 10.
Answer: 90
- 31 rounds to 30
- 30 × 3 = 90
The exact answer is 93.
5.Estimate 296 + 830 by rounding each number to the nearest 100.
Answer: 1,100
- 296 rounds to 300; 830 rounds to 800
- 300 + 800 = 1,100
The exact answer is 1,126, close to the estimate.
6.Estimate 86 × 8 by rounding 86 to the nearest 10.
Answer: 720
- 86 rounds to 90
- 90 × 8 = 720
The exact answer is 688.
7.Estimate 884 − 476 by rounding each number to the nearest 100.
Answer: 400
- 884 rounds to 900; 476 rounds to 500
- 900 − 500 = 400
The exact answer is 408, close to the estimate.
8.Estimate 28 × 5 by rounding 28 to the nearest 10.
Answer: 150
- 28 rounds to 30
- 30 × 5 = 150
The exact answer is 140.
9.Estimate 658 + 570 by rounding each number to the nearest 100.
Answer: 1,300
- 658 rounds to 700; 570 rounds to 600
- 700 + 600 = 1,300
The exact answer is 1,228, close to the estimate.
10.Estimate 23 × 9 by rounding 23 to the nearest 10.
Answer: 180
- 23 rounds to 20
- 20 × 9 = 180
The exact answer is 207.
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.