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Year 5 Mental Addition and Subtraction Strategies Worksheet — Level 3 — Answers

Answer sheet with worked solutions for the Year 5 addition worksheet.

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Success TutoringWorksheetsAnswer sheetYear 5 · Mathematics · Addition

Year 5 Mental Addition and Subtraction Strategies Worksheet — Level 3 — Answers

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

1.140 + 18 = 140 + 20 − (answer space) = (answer space)

Answer: 2, 158

  1. 140 + 20 = 160
  2. 160 − 2 = 158
2.34 − 18 = 34 − 20 + (answer space) = (answer space)

Answer: 2, 16

  1. 34 − 20 = 14
  2. I took away 2 too many, so add it back: 14 + 2 = 16
3.52 − 3 = 52 − 2 − (answer space) = (answer space)

Answer: 1, 49

  1. 52 − 2 = 50 (back to a ten)
  2. 50 − 1 = 49
4.138 + 19 = 138 + 20 − (answer space) = (answer space)

Answer: 1, 157

  1. 138 + 20 = 158
  2. 158 − 1 = 157
5.163 − 99 = 163 − 100 + (answer space) = (answer space)

Answer: 1, 64

  1. 163 − 100 = 63
  2. I took away 1 too many, so add it back: 63 + 1 = 64
6.173 − 8 = 173 − 3 − (answer space) = (answer space)

Answer: 5, 165

  1. 173 − 3 = 170 (back to a ten)
  2. 170 − 5 = 165
7.192 + 38 = 192 + 40 − (answer space) = (answer space)

Answer: 2, 230

  1. 192 + 40 = 232
  2. 232 − 2 = 230
8.118 − 99 = 118 − 100 + (answer space) = (answer space)

Answer: 1, 19

  1. 118 − 100 = 18
  2. I took away 1 too many, so add it back: 18 + 1 = 19
9.94 − 6 = 94 − 4 − (answer space) = (answer space)

Answer: 2, 88

  1. 94 − 4 = 90 (back to a ten)
  2. 90 − 2 = 88
10.88 + 39 = 88 + 40 − (answer space) = (answer space)

Answer: 1, 127

  1. 88 + 40 = 128
  2. 128 − 1 = 127
11.77 − 28 = 77 − 30 + (answer space) = (answer space)

Answer: 2, 49

  1. 77 − 30 = 47
  2. I took away 2 too many, so add it back: 47 + 2 = 49
12.101 − 8 = 101 − 1 − (answer space) = (answer space)

Answer: 7, 93

  1. 101 − 1 = 100 (back to a ten)
  2. 100 − 7 = 93
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