3rd Grade Mental Addition and Subtraction Strategies Worksheet — Level 2 — Practice Set 2 — 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 2 — Answers
Fill in each step of the strategy, then write the answer.
1.59 + 2 = 59 + 1 + (answer space) = (answer space)
Answer: 1, 61
- 59 + 1 = 60 (a ten)
- 60 + 1 = 61
2.87 + 9 = 87 + 10 − (answer space) = (answer space)
Answer: 1, 96
- 87 + 10 = 97
- 97 − 1 = 96
3.36 + 37 = (answer space) + (answer space) + 1 = (answer space)
Answer: 36, 36, 73
- Double 36 is 72
- 72 + 1 = 73
4.55 + 8 = 55 + 5 + (answer space) = (answer space)
Answer: 3, 63
- 55 + 5 = 60 (a ten)
- 60 + 3 = 63
5.17 + 9 = 17 + 10 − (answer space) = (answer space)
Answer: 1, 26
- 17 + 10 = 27
- 27 − 1 = 26
6.22 + 23 = (answer space) + (answer space) + 1 = (answer space)
Answer: 22, 22, 45
- Double 22 is 44
- 44 + 1 = 45
7.68 + 7 = 68 + 2 + (answer space) = (answer space)
Answer: 5, 75
- 68 + 2 = 70 (a ten)
- 70 + 5 = 75
8.61 + 9 = 61 + 10 − (answer space) = (answer space)
Answer: 1, 70
- 61 + 10 = 71
- 71 − 1 = 70
9.53 + 54 = (answer space) + (answer space) + 1 = (answer space)
Answer: 53, 53, 107
- Double 53 is 106
- 106 + 1 = 107
10.79 + 7 = 79 + 1 + (answer space) = (answer space)
Answer: 6, 86
- 79 + 1 = 80 (a ten)
- 80 + 6 = 86
11.67 + 9 = 67 + 10 − (answer space) = (answer space)
Answer: 1, 76
- 67 + 10 = 77
- 77 − 1 = 76
12.19 + 18 = (answer space) + (answer space) + 1 = (answer space)
Answer: 18, 18, 37
- Double 18 is 36
- 36 + 1 = 37
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.