Year 3 Mental Addition and Subtraction Strategies Worksheet — Level 2 — Practice Set 4 — 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 4 — Answers
Fill in each step of the strategy, then write the answer.
1.87 + 8 = 87 + 3 + (answer space) = (answer space)
Answer: 5, 95
- 87 + 3 = 90 (a ten)
- 90 + 5 = 95
2.55 + 9 = 55 + 10 − (answer space) = (answer space)
Answer: 1, 64
- 55 + 10 = 65
- 65 − 1 = 64
3.81 + 80 = (answer space) + (answer space) + 1 = (answer space)
Answer: 80, 80, 161
- Double 80 is 160
- 160 + 1 = 161
4.38 + 3 = 38 + 2 + (answer space) = (answer space)
Answer: 1, 41
- 38 + 2 = 40 (a ten)
- 40 + 1 = 41
5.69 + 9 = 69 + 10 − (answer space) = (answer space)
Answer: 1, 78
- 69 + 10 = 79
- 79 − 1 = 78
6.25 + 26 = (answer space) + (answer space) + 1 = (answer space)
Answer: 25, 25, 51
- Double 25 is 50
- 50 + 1 = 51
7.39 + 6 = 39 + 1 + (answer space) = (answer space)
Answer: 5, 45
- 39 + 1 = 40 (a ten)
- 40 + 5 = 45
8.52 + 9 = 52 + 10 − (answer space) = (answer space)
Answer: 1, 61
- 52 + 10 = 62
- 62 − 1 = 61
9.16 + 15 = (answer space) + (answer space) + 1 = (answer space)
Answer: 15, 15, 31
- Double 15 is 30
- 30 + 1 = 31
10.47 + 4 = 47 + 3 + (answer space) = (answer space)
Answer: 1, 51
- 47 + 3 = 50 (a ten)
- 50 + 1 = 51
11.11 + 9 = 11 + 10 − (answer space) = (answer space)
Answer: 1, 20
- 11 + 10 = 21
- 21 − 1 = 20
12.42 + 41 = (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.