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

Answer sheet with worked solutions for the Year 3 addition worksheet.

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Success TutoringWorksheetsAnswer sheetYear 3 · Mathematics · Addition

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

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

1.22 + 9 = 22 + 10 − (answer space) = (answer space)

Answer: 1, 31

  1. 22 + 10 = 32
  2. 32 − 1 = 31
2.127 − 28 = 127 − 30 + (answer space) = (answer space)

Answer: 2, 99

  1. 127 − 30 = 97
  2. I took away 2 too many, so add it back: 97 + 2 = 99
3.51 − 7 = 51 − 1 − (answer space) = (answer space)

Answer: 6, 44

  1. 51 − 1 = 50 (back to a ten)
  2. 50 − 6 = 44
4.45 + 28 = 45 + 30 − (answer space) = (answer space)

Answer: 2, 73

  1. 45 + 30 = 75
  2. 75 − 2 = 73
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
6.123 − 9 = 123 − 3 − (answer space) = (answer space)

Answer: 6, 114

  1. 123 − 3 = 120 (back to a ten)
  2. 120 − 6 = 114
7.129 + 9 = 129 + 10 − (answer space) = (answer space)

Answer: 1, 138

  1. 129 + 10 = 139
  2. 139 − 1 = 138
8.188 − 98 = 188 − 100 + (answer space) = (answer space)

Answer: 2, 90

  1. 188 − 100 = 88
  2. I took away 2 too many, so add it back: 88 + 2 = 90
9.101 − 5 = 101 − 1 − (answer space) = (answer space)

Answer: 4, 96

  1. 101 − 1 = 100 (back to a ten)
  2. 100 − 4 = 96
10.162 + 19 = 162 + 20 − (answer space) = (answer space)

Answer: 1, 181

  1. 162 + 20 = 182
  2. 182 − 1 = 181
11.57 − 9 = 57 − 10 + (answer space) = (answer space)

Answer: 1, 48

  1. 57 − 10 = 47
  2. I took away 1 too many, so add it back: 47 + 1 = 48
12.54 − 6 = 54 − 4 − (answer space) = (answer space)

Answer: 2, 48

  1. 54 − 4 = 50 (back to a ten)
  2. 50 − 2 = 48
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