Year 1 Missing Numbers in Number Sentences Worksheet — Level 1 — Practice Set 2 — 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 2 — Answers
Write the missing number. Use addition to check subtraction, and subtraction to check addition.
1. (answer space) + 15 = 20
Answer: 5
- 20 − 15 = 5
2.12 + (answer space) = 13
Answer: 1
- 13 − 12 = 1
3. (answer space) − 3 = 6
Answer: 9
- 6 + 3 = 9
4.1 + (answer space) = 6
Answer: 5
- 6 − 1 = 5
5.13 − (answer space) = 5
Answer: 8
- 13 − 5 = 8
6. (answer space) − 5 = 3
Answer: 8
- 3 + 5 = 8
7. (answer space) − 11 = 2
Answer: 13
- 2 + 11 = 13
8.9 + (answer space) = 12
Answer: 3
- 12 − 9 = 3
9. (answer space) − 3 = 2
Answer: 5
- 2 + 3 = 5
10.3 + (answer space) = 7
Answer: 4
- 7 − 3 = 4
11.5 + (answer space) = 7
Answer: 2
- 7 − 5 = 2
12.11 + (answer space) = 19
Answer: 8
- 19 − 11 = 8
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.