3rd Grade Estimating Sums, Differences and Products Worksheet — Level 1 — Practice Set 3 — Answers
Answer sheet with worked solutions for the 3rd Grade place value worksheet.
Success TutoringWorksheetsAnswer sheet3rd Grade · Mathematics · Place Value3rd Grade Estimating Sums, Differences and Products Worksheet — Level 1 — Practice Set 3 — Answers
Round each number first, then work out the estimate in your head.
1.Estimate 76 − 45 by rounding each number to the nearest 10.
Answer: 30
- 76 rounds to 80; 45 rounds to 50
- 80 − 50 = 30
The exact answer is 31, close to the estimate.
2.Estimate 74 − 26 by rounding each number to the nearest 10.
Answer: 40
- 74 rounds to 70; 26 rounds to 30
- 70 − 30 = 40
The exact answer is 48, close to the estimate.
3.Estimate 95 − 45 by rounding each number to the nearest 10.
Answer: 50
- 95 rounds to 100; 45 rounds to 50
- 100 − 50 = 50
The exact answer is 50, close to the estimate.
4.Estimate 21 − 11 by rounding each number to the nearest 10.
Answer: 10
- 21 rounds to 20; 11 rounds to 10
- 20 − 10 = 10
The exact answer is 10, close to the estimate.
5.Estimate 85 + 44 by rounding each number to the nearest 10.
Answer: 130
- 85 rounds to 90; 44 rounds to 40
- 90 + 40 = 130
The exact answer is 129, close to the estimate.
6.Estimate 59 + 42 by rounding each number to the nearest 10.
Answer: 100
- 59 rounds to 60; 42 rounds to 40
- 60 + 40 = 100
The exact answer is 101, close to the estimate.
7.Estimate 71 − 36 by rounding each number to the nearest 10.
Answer: 30
- 71 rounds to 70; 36 rounds to 40
- 70 − 40 = 30
The exact answer is 35, close to the estimate.
8.Estimate 78 + 92 by rounding each number to the nearest 10.
Answer: 170
- 78 rounds to 80; 92 rounds to 90
- 80 + 90 = 170
The exact answer is 170, close to the estimate.
9.Estimate 53 + 78 by rounding each number to the nearest 10.
Answer: 130
- 53 rounds to 50; 78 rounds to 80
- 50 + 80 = 130
The exact answer is 131, close to the estimate.
10.Estimate 66 − 62 by rounding each number to the nearest 10.
Answer: 10
- 66 rounds to 70; 62 rounds to 60
- 70 − 60 = 10
The exact answer is 4, 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.
- Celebrate what went well first, then pick one thing to work on next.