Year 4 Mental Addition and Subtraction Strategies Worksheet — Level 1 — Practice Set 2 — Answers
Answer sheet with worked solutions for the Year 4 addition worksheet.
Year 4 Mental Addition and Subtraction Strategies Worksheet — Level 1 — Practice Set 2 — Answers
Fill in each step of the strategy, then write the answer.
1.9 + 3 = 9 + 1 + (answer space) = (answer space)
Answer: 2, 12
- 9 + 1 = 10 (a ten)
- 10 + 2 = 12
2.9 + 6 = 9 + 1 + (answer space) = (answer space)
Answer: 5, 15
- 9 + 1 = 10 (a ten)
- 10 + 5 = 15
3.8 + 7 = (answer space) + (answer space) + 1 = (answer space)
Answer: 7, 7, 15
- Double 7 is 14
- 14 + 1 = 15
4.6 + 6 = 6 + 4 + (answer space) = (answer space)
Answer: 2, 12
- 6 + 4 = 10 (a ten)
- 10 + 2 = 12
5.6 + 9 = 6 + 4 + (answer space) = (answer space)
Answer: 5, 15
- 6 + 4 = 10 (a ten)
- 10 + 5 = 15
6.4 + 3 = (answer space) + (answer space) + 1 = (answer space)
Answer: 3, 3, 7
- Double 3 is 6
- 6 + 1 = 7
7.8 + 7 = 8 + 2 + (answer space) = (answer space)
Answer: 5, 15
- 8 + 2 = 10 (a ten)
- 10 + 5 = 15
8.8 + 8 = 8 + 2 + (answer space) = (answer space)
Answer: 6, 16
- 8 + 2 = 10 (a ten)
- 10 + 6 = 16
9.7 + 6 = (answer space) + (answer space) + 1 = (answer space)
Answer: 6, 6, 13
- Double 6 is 12
- 12 + 1 = 13
10.6 + 5 = 6 + 4 + (answer space) = (answer space)
Answer: 1, 11
- 6 + 4 = 10 (a ten)
- 10 + 1 = 11
11.7 + 8 = 7 + 3 + (answer space) = (answer space)
Answer: 5, 15
- 7 + 3 = 10 (a ten)
- 10 + 5 = 15
12.3 + 4 = (answer space) + (answer space) + 1 = (answer space)
Answer: 3, 3, 7
- Double 3 is 6
- 6 + 1 = 7
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.