Year 3 Mental Addition and Subtraction Strategies Worksheet — Level 1 — 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 1 — Practice Set 4 — Answers
Fill in each step of the strategy, then write the answer.
1.9 + 5 = 9 + 1 + (answer space) = (answer space)
Answer: 4, 14
- 9 + 1 = 10 (a ten)
- 10 + 4 = 14
2.8 + 8 = 8 + 2 + (answer space) = (answer space)
Answer: 6, 16
- 8 + 2 = 10 (a ten)
- 10 + 6 = 16
3.5 + 4 = (answer space) + (answer space) + 1 = (answer space)
Answer: 4, 4, 9
- Double 4 is 8
- 8 + 1 = 9
4.7 + 5 = 7 + 3 + (answer space) = (answer space)
Answer: 2, 12
- 7 + 3 = 10 (a ten)
- 10 + 2 = 12
5.9 + 2 = 9 + 1 + (answer space) = (answer space)
Answer: 1, 11
- 9 + 1 = 10 (a ten)
- 10 + 1 = 11
6.5 + 6 = (answer space) + (answer space) + 1 = (answer space)
Answer: 5, 5, 11
- Double 5 is 10
- 10 + 1 = 11
7.7 + 7 = 7 + 3 + (answer space) = (answer space)
Answer: 4, 14
- 7 + 3 = 10 (a ten)
- 10 + 4 = 14
8.8 + 7 = 8 + 2 + (answer space) = (answer space)
Answer: 5, 15
- 8 + 2 = 10 (a ten)
- 10 + 5 = 15
9.7 + 8 = (answer space) + (answer space) + 1 = (answer space)
Answer: 7, 7, 15
- Double 7 is 14
- 14 + 1 = 15
10.9 + 4 = 9 + 1 + (answer space) = (answer space)
Answer: 3, 13
- 9 + 1 = 10 (a ten)
- 10 + 3 = 13
11.7 + 9 = 7 + 3 + (answer space) = (answer space)
Answer: 6, 16
- 7 + 3 = 10 (a ten)
- 10 + 6 = 16
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.