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.
1.35 + 8 = 35 + 5 + (answer space) = (answer space)
Answer: 3, 43
- 35 + 5 = 40 (a ten)
- 40 + 3 = 43
2.57 + 9 = 57 + 10 − (answer space) = (answer space)
Answer: 1, 66
- 57 + 10 = 67
- 67 − 1 = 66
3.39 + 40 = (answer space) + (answer space) + 1 = (answer space)
Answer: 39, 39, 79
- Double 39 is 78
- 78 + 1 = 79
4.36 + 5 = 36 + 4 + (answer space) = (answer space)
Answer: 1, 41
- 36 + 4 = 40 (a ten)
- 40 + 1 = 41
5.33 + 9 = 33 + 10 − (answer space) = (answer space)
Answer: 1, 42
- 33 + 10 = 43
- 43 − 1 = 42
6.62 + 63 = (answer space) + (answer space) + 1 = (answer space)
Answer: 62, 62, 125
- Double 62 is 124
- 124 + 1 = 125
7.19 + 6 = 19 + 1 + (answer space) = (answer space)
Answer: 5, 25
- 19 + 1 = 20 (a ten)
- 20 + 5 = 25
8.29 + 9 = 29 + 10 − (answer space) = (answer space)
Answer: 1, 38
- 29 + 10 = 39
- 39 − 1 = 38
9.49 + 50 = (answer space) + (answer space) + 1 = (answer space)
Answer: 49, 49, 99
- Double 49 is 98
- 98 + 1 = 99
10.48 + 7 = 48 + 2 + (answer space) = (answer space)
Answer: 5, 55
- 48 + 2 = 50 (a ten)
- 50 + 5 = 55
11.16 + 9 = 16 + 10 − (answer space) = (answer space)
Answer: 1, 25
- 16 + 10 = 26
- 26 − 1 = 25
12.64 + 65 = (answer space) + (answer space) + 1 = (answer space)
Answer: 64, 64, 129
- Double 64 is 128
- 128 + 1 = 129
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.