Year 1 Missing Numbers in Number Sentences Worksheet — Level 1 — Practice Set 3 — Answers
Answer sheet with worked solutions for the Year 1 addition worksheet.
Success TutoringWorksheetsAnswer sheetYear 1 · Mathematics · AdditionYear 1 Missing Numbers in Number Sentences Worksheet — Level 1 — Practice Set 3 — Answers
Write the missing number. Use addition to check subtraction, and subtraction to check addition.
1.15 + (answer space) = 18
Answer: 3
- 18 − 15 = 3
2.10 + (answer space) = 16
Answer: 6
- 16 − 10 = 6
3. (answer space) − 2 = 3
Answer: 5
- 3 + 2 = 5
4.12 − (answer space) = 9
Answer: 3
- 12 − 9 = 3
5.18 − (answer space) = 16
Answer: 2
- 18 − 16 = 2
6. (answer space) − 3 = 5
Answer: 8
- 5 + 3 = 8
7. (answer space) + 4 = 13
Answer: 9
- 13 − 4 = 9
8.11 + (answer space) = 19
Answer: 8
- 19 − 11 = 8
9. (answer space) + 2 = 5
Answer: 3
- 5 − 2 = 3
10. (answer space) + 4 = 17
Answer: 13
- 17 − 4 = 13
11. (answer space) − 8 = 11
Answer: 19
- 11 + 8 = 19
12.4 + (answer space) = 9
Answer: 5
- 9 − 4 = 5
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.