Year 7 Estimating Sums, Differences and Products Worksheet — Level 3 — Practice Set 3 — Answers
Answer sheet with worked solutions for the Year 7 place value worksheet.
Success TutoringWorksheetsAnswer sheetYear 7 · Mathematics · Place ValueYear 7 Estimating Sums, Differences and Products Worksheet — Level 3 — Practice Set 3 — Answers
Round each number first, then work out the estimate in your head.
1.Estimate 3,412 − 2,882 by rounding each number to the nearest 100.
Answer: 500
- 3,412 rounds to 3,400; 2,882 rounds to 2,900
- 3,400 − 2,900 = 500
The exact answer is 530, close to the estimate.
2.Estimate 31 × 82 by rounding each number to the nearest 10.
Answer: 2,400
- 31 rounds to 30; 82 rounds to 80
- 30 × 80 = 2,400
The exact answer is 2,542.
3.Estimate 66 × 5 by rounding 66 to the nearest 10.
Answer: 350
- 66 rounds to 70
- 70 × 5 = 350
The exact answer is 330.
4.Estimate 2,998 + 6,541 by rounding each number to the nearest 1,000.
Answer: 10,000
- 2,998 rounds to 3,000; 6,541 rounds to 7,000
- 3,000 + 7,000 = 10,000
The exact answer is 9,539, close to the estimate.
5.Estimate 94 × 19 by rounding each number to the nearest 10.
Answer: 1,800
- 94 rounds to 90; 19 rounds to 20
- 90 × 20 = 1,800
The exact answer is 1,786.
6.Estimate 55 × 33 by rounding each number to the nearest 10.
Answer: 1,800
- 55 rounds to 60; 33 rounds to 30
- 60 × 30 = 1,800
The exact answer is 1,815.
7.Estimate 6,599 + 4,497 by rounding each number to the nearest 1,000.
Answer: 11,000
- 6,599 rounds to 7,000; 4,497 rounds to 4,000
- 7,000 + 4,000 = 11,000
The exact answer is 11,096, close to the estimate.
8.Estimate 94 × 59 by rounding each number to the nearest 10.
Answer: 5,400
- 94 rounds to 90; 59 rounds to 60
- 90 × 60 = 5,400
The exact answer is 5,546.
9.Estimate 57 × 8 by rounding 57 to the nearest 10.
Answer: 480
- 57 rounds to 60
- 60 × 8 = 480
The exact answer is 456.
10.Estimate 3,665 − 1,836 by rounding each number to the nearest 1,000.
Answer: 2,000
- 3,665 rounds to 4,000; 1,836 rounds to 2,000
- 4,000 − 2,000 = 2,000
The exact answer is 1,829, close to the estimate.
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.
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