Year 3 Mental Addition and Subtraction Strategies Worksheet — Level 2 — Practice Set 3 — Answers
Answer sheet with worked solutions for the Year 3 addition worksheet.
Success TutoringWorksheetsAnswer sheetYear 3 · Mathematics · AdditionYear 3 Mental Addition and Subtraction Strategies Worksheet — Level 2 — Practice Set 3 — Answers
Fill in each step of the strategy, then write the answer.
1.18 + 8 = 18 + 2 + (answer space) = (answer space)
Answer: 6, 26
- 18 + 2 = 20 (a ten)
- 20 + 6 = 26
2.43 + 9 = 43 + 10 − (answer space) = (answer space)
Answer: 1, 52
- 43 + 10 = 53
- 53 − 1 = 52
3.51 + 52 = (answer space) + (answer space) + 1 = (answer space)
Answer: 51, 51, 103
- Double 51 is 102
- 102 + 1 = 103
4.35 + 8 = 35 + 5 + (answer space) = (answer space)
Answer: 3, 43
- 35 + 5 = 40 (a ten)
- 40 + 3 = 43
5.87 + 9 = 87 + 10 − (answer space) = (answer space)
Answer: 1, 96
- 87 + 10 = 97
- 97 − 1 = 96
6.40 + 39 = (answer space) + (answer space) + 1 = (answer space)
Answer: 39, 39, 79
- Double 39 is 78
- 78 + 1 = 79
7.16 + 8 = 16 + 4 + (answer space) = (answer space)
Answer: 4, 24
- 16 + 4 = 20 (a ten)
- 20 + 4 = 24
8.72 + 9 = 72 + 10 − (answer space) = (answer space)
Answer: 1, 81
- 72 + 10 = 82
- 82 − 1 = 81
9.45 + 44 = (answer space) + (answer space) + 1 = (answer space)
Answer: 44, 44, 89
- Double 44 is 88
- 88 + 1 = 89
10.78 + 3 = 78 + 2 + (answer space) = (answer space)
Answer: 1, 81
- 78 + 2 = 80 (a ten)
- 80 + 1 = 81
11.35 + 9 = 35 + 10 − (answer space) = (answer space)
Answer: 1, 44
- 35 + 10 = 45
- 45 − 1 = 44
12.33 + 32 = (answer space) + (answer space) + 1 = (answer space)
Answer: 32, 32, 65
- Double 32 is 64
- 64 + 1 = 65
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.