Year 4 Mental Addition and Subtraction Strategies Worksheet — Level 2 — Practice Set 4 — Answers
Answer sheet with worked solutions for the Year 4 addition worksheet.
Success TutoringWorksheetsAnswer sheetYear 4 · Mathematics · AdditionYear 4 Mental Addition and Subtraction Strategies Worksheet — Level 2 — Practice Set 4 — Answers
Fill in each step of the strategy, then write the answer.
1.29 + 8 = 29 + 1 + (answer space) = (answer space)
Answer: 7, 37
- 29 + 1 = 30 (a ten)
- 30 + 7 = 37
2.34 + 9 = 34 + 10 − (answer space) = (answer space)
Answer: 1, 43
- 34 + 10 = 44
- 44 − 1 = 43
3.82 + 81 = (answer space) + (answer space) + 1 = (answer space)
Answer: 81, 81, 163
- Double 81 is 162
- 162 + 1 = 163
4.48 + 4 = 48 + 2 + (answer space) = (answer space)
Answer: 2, 52
- 48 + 2 = 50 (a ten)
- 50 + 2 = 52
5.77 + 9 = 77 + 10 − (answer space) = (answer space)
Answer: 1, 86
- 77 + 10 = 87
- 87 − 1 = 86
6.21 + 20 = (answer space) + (answer space) + 1 = (answer space)
Answer: 20, 20, 41
- Double 20 is 40
- 40 + 1 = 41
7.38 + 7 = 38 + 2 + (answer space) = (answer space)
Answer: 5, 45
- 38 + 2 = 40 (a ten)
- 40 + 5 = 45
8.73 + 9 = 73 + 10 − (answer space) = (answer space)
Answer: 1, 82
- 73 + 10 = 83
- 83 − 1 = 82
9.84 + 83 = (answer space) + (answer space) + 1 = (answer space)
Answer: 83, 83, 167
- Double 83 is 166
- 166 + 1 = 167
10.67 + 4 = 67 + 3 + (answer space) = (answer space)
Answer: 1, 71
- 67 + 3 = 70 (a ten)
- 70 + 1 = 71
11.19 + 9 = 19 + 10 − (answer space) = (answer space)
Answer: 1, 28
- 19 + 10 = 29
- 29 − 1 = 28
12.53 + 54 = (answer space) + (answer space) + 1 = (answer space)
Answer: 53, 53, 107
- Double 53 is 106
- 106 + 1 = 107
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.