3rd Grade Mental Addition and Subtraction Strategies Worksheet — Level 2 — Practice Set 4 — Answers
Answer sheet with worked solutions for the 3rd Grade addition worksheet.
Success TutoringWorksheetsAnswer sheet3rd Grade · Mathematics · Addition3rd Grade Mental Addition and Subtraction Strategies Worksheet — Level 2 — Practice Set 4 — Answers
Fill in each step of the strategy, then write the answer.
1.86 + 9 = 86 + 4 + (answer space) = (answer space)
Answer: 5, 95
- 86 + 4 = 90 (a ten)
- 90 + 5 = 95
2.69 + 9 = 69 + 10 − (answer space) = (answer space)
Answer: 1, 78
- 69 + 10 = 79
- 79 − 1 = 78
3.51 + 50 = (answer space) + (answer space) + 1 = (answer space)
Answer: 50, 50, 101
- Double 50 is 100
- 100 + 1 = 101
4.75 + 8 = 75 + 5 + (answer space) = (answer space)
Answer: 3, 83
- 75 + 5 = 80 (a ten)
- 80 + 3 = 83
5.86 + 9 = 86 + 10 − (answer space) = (answer space)
Answer: 1, 95
- 86 + 10 = 96
- 96 − 1 = 95
6.53 + 52 = (answer space) + (answer space) + 1 = (answer space)
Answer: 52, 52, 105
- Double 52 is 104
- 104 + 1 = 105
7.17 + 5 = 17 + 3 + (answer space) = (answer space)
Answer: 2, 22
- 17 + 3 = 20 (a ten)
- 20 + 2 = 22
8.27 + 9 = 27 + 10 − (answer space) = (answer space)
Answer: 1, 36
- 27 + 10 = 37
- 37 − 1 = 36
9.22 + 23 = (answer space) + (answer space) + 1 = (answer space)
Answer: 22, 22, 45
- Double 22 is 44
- 44 + 1 = 45
10.26 + 6 = 26 + 4 + (answer space) = (answer space)
Answer: 2, 32
- 26 + 4 = 30 (a ten)
- 30 + 2 = 32
11.17 + 9 = 17 + 10 − (answer space) = (answer space)
Answer: 1, 26
- 17 + 10 = 27
- 27 − 1 = 26
12.41 + 42 = (answer space) + (answer space) + 1 = (answer space)
Answer: 41, 41, 83
- Double 41 is 82
- 82 + 1 = 83
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.