2nd Grade Mental Addition and Subtraction Strategies Worksheet — Level 2 — Practice Set 3 — Answers
Answer sheet with worked solutions for the 2nd Grade addition worksheet.
Success TutoringWorksheetsAnswer sheet2nd Grade · Mathematics · Addition2nd Grade Mental Addition and Subtraction Strategies Worksheet — Level 2 — Practice Set 3 — Answers
Fill in each step of the strategy, then write the answer.
1.45 + 9 = 45 + 5 + (answer space) = (answer space)
Answer: 4, 54
- 45 + 5 = 50 (a ten)
- 50 + 4 = 54
2.65 + 9 = 65 + 10 − (answer space) = (answer space)
Answer: 1, 74
- 65 + 10 = 75
- 75 − 1 = 74
3.36 + 37 = (answer space) + (answer space) + 1 = (answer space)
Answer: 36, 36, 73
- Double 36 is 72
- 72 + 1 = 73
4.85 + 7 = 85 + 5 + (answer space) = (answer space)
Answer: 2, 92
- 85 + 5 = 90 (a ten)
- 90 + 2 = 92
5.55 + 9 = 55 + 10 − (answer space) = (answer space)
Answer: 1, 64
- 55 + 10 = 65
- 65 − 1 = 64
6.64 + 63 = (answer space) + (answer space) + 1 = (answer space)
Answer: 63, 63, 127
- Double 63 is 126
- 126 + 1 = 127
7.28 + 8 = 28 + 2 + (answer space) = (answer space)
Answer: 6, 36
- 28 + 2 = 30 (a ten)
- 30 + 6 = 36
8.40 + 9 = 40 + 10 − (answer space) = (answer space)
Answer: 1, 49
- 40 + 10 = 50
- 50 − 1 = 49
9.55 + 54 = (answer space) + (answer space) + 1 = (answer space)
Answer: 54, 54, 109
- Double 54 is 108
- 108 + 1 = 109
10.19 + 9 = 19 + 1 + (answer space) = (answer space)
Answer: 8, 28
- 19 + 1 = 20 (a ten)
- 20 + 8 = 28
11.67 + 9 = 67 + 10 − (answer space) = (answer space)
Answer: 1, 76
- 67 + 10 = 77
- 77 − 1 = 76
12.21 + 20 = (answer space) + (answer space) + 1 = (answer space)
Answer: 20, 20, 41
- Double 20 is 40
- 40 + 1 = 41
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.