Year 3 Estimating Sums, Differences and Products Worksheet — Level 2 — Practice Set 2 — 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 2 — Answers
Round each number first, then work out the estimate in your head.
1.Estimate 642 − 277 by rounding each number to the nearest 100.
Answer: 300
- 642 rounds to 600; 277 rounds to 300
- 600 − 300 = 300
The exact answer is 365, close to the estimate.
2.Estimate 12 × 4 by rounding 12 to the nearest 10.
Answer: 40
- 12 rounds to 10
- 10 × 4 = 40
The exact answer is 48.
3.Estimate 622 + 320 by rounding each number to the nearest 100.
Answer: 900
- 622 rounds to 600; 320 rounds to 300
- 600 + 300 = 900
The exact answer is 942, close to the estimate.
4.Estimate 97 × 7 by rounding 97 to the nearest 10.
Answer: 700
- 97 rounds to 100
- 100 × 7 = 700
The exact answer is 679.
5.Estimate 950 + 268 by rounding each number to the nearest 100.
Answer: 1,300
- 950 rounds to 1,000; 268 rounds to 300
- 1,000 + 300 = 1,300
The exact answer is 1,218, close to the estimate.
6.Estimate 57 × 5 by rounding 57 to the nearest 10.
Answer: 300
- 57 rounds to 60
- 60 × 5 = 300
The exact answer is 285.
7.Estimate 649 + 274 by rounding each number to the nearest 100.
Answer: 900
- 649 rounds to 600; 274 rounds to 300
- 600 + 300 = 900
The exact answer is 923, close to the estimate.
8.Estimate 78 × 9 by rounding 78 to the nearest 10.
Answer: 720
- 78 rounds to 80
- 80 × 9 = 720
The exact answer is 702.
9.Estimate 738 + 182 by rounding each number to the nearest 100.
Answer: 900
- 738 rounds to 700; 182 rounds to 200
- 700 + 200 = 900
The exact answer is 920, close to the estimate.
10.Estimate 98 × 4 by rounding 98 to the nearest 10.
Answer: 400
- 98 rounds to 100
- 100 × 4 = 400
The exact answer is 392.
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.