Success TutoringWorksheets

Year 2 Mental Addition and Subtraction Strategies Worksheet — Level 3 — Answers

Answer sheet with worked solutions for the Year 2 addition worksheet.

Download answers PDFPrint answersBack to worksheet
Success TutoringWorksheetsAnswer sheetYear 2 · Mathematics · Addition

Year 2 Mental Addition and Subtraction Strategies Worksheet — Level 3 — Answers

Fill in each step of the strategy, then write the answer.

1.45 + 39 = 45 + 40 − (answer space) = (answer space)

Answer: 1, 84

  1. 45 + 40 = 85
  2. 85 − 1 = 84
2.158 − 48 = 158 − 50 + (answer space) = (answer space)

Answer: 2, 110

  1. 158 − 50 = 108
  2. I took away 2 too many, so add it back: 108 + 2 = 110
3.24 − 6 = 24 − 4 − (answer space) = (answer space)

Answer: 2, 18

  1. 24 − 4 = 20 (back to a ten)
  2. 20 − 2 = 18
4.35 + 9 = 35 + 10 − (answer space) = (answer space)

Answer: 1, 44

  1. 35 + 10 = 45
  2. 45 − 1 = 44
5.92 − 59 = 92 − 60 + (answer space) = (answer space)

Answer: 1, 33

  1. 92 − 60 = 32
  2. I took away 1 too many, so add it back: 32 + 1 = 33
6.143 − 6 = 143 − 3 − (answer space) = (answer space)

Answer: 3, 137

  1. 143 − 3 = 140 (back to a ten)
  2. 140 − 3 = 137
7.93 + 28 = 93 + 30 − (answer space) = (answer space)

Answer: 2, 121

  1. 93 + 30 = 123
  2. 123 − 2 = 121
8.99 − 29 = 99 − 30 + (answer space) = (answer space)

Answer: 1, 70

  1. 99 − 30 = 69
  2. I took away 1 too many, so add it back: 69 + 1 = 70
9.171 − 3 = 171 − 1 − (answer space) = (answer space)

Answer: 2, 168

  1. 171 − 1 = 170 (back to a ten)
  2. 170 − 2 = 168
10.47 + 39 = 47 + 40 − (answer space) = (answer space)

Answer: 1, 86

  1. 47 + 40 = 87
  2. 87 − 1 = 86
11.114 − 29 = 114 − 30 + (answer space) = (answer space)

Answer: 1, 85

  1. 114 − 30 = 84
  2. I took away 1 too many, so add it back: 84 + 1 = 85
12.103 − 5 = 103 − 3 − (answer space) = (answer space)

Answer: 2, 98

  1. 103 − 3 = 100 (back to a ten)
  2. 100 − 2 = 98
Free worksheets at worksheets.successtutoring.com · © Success Tutoring · Free for personal and classroom use

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.

Great work. Here's what to try next: