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Year 4 Mental Addition and Subtraction Strategies Worksheet — Level 3 — Answers

Answer sheet with worked solutions for the Year 4 addition worksheet.

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Success TutoringWorksheetsAnswer sheetYear 4 · Mathematics · Addition

Year 4 Mental Addition and Subtraction Strategies Worksheet — Level 3 — Answers

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

1.113 + 39 = 113 + 40 − (answer space) = (answer space)

Answer: 1, 152

  1. 113 + 40 = 153
  2. 153 − 1 = 152
2.56 − 29 = 56 − 30 + (answer space) = (answer space)

Answer: 1, 27

  1. 56 − 30 = 26
  2. I took away 1 too many, so add it back: 26 + 1 = 27
3.164 − 9 = 164 − 4 − (answer space) = (answer space)

Answer: 5, 155

  1. 164 − 4 = 160 (back to a ten)
  2. 160 − 5 = 155
4.56 + 28 = 56 + 30 − (answer space) = (answer space)

Answer: 2, 84

  1. 56 + 30 = 86
  2. 86 − 2 = 84
5.182 − 98 = 182 − 100 + (answer space) = (answer space)

Answer: 2, 84

  1. 182 − 100 = 82
  2. I took away 2 too many, so add it back: 82 + 2 = 84
6.114 − 9 = 114 − 4 − (answer space) = (answer space)

Answer: 5, 105

  1. 114 − 4 = 110 (back to a ten)
  2. 110 − 5 = 105
7.171 + 48 = 171 + 50 − (answer space) = (answer space)

Answer: 2, 219

  1. 171 + 50 = 221
  2. 221 − 2 = 219
8.107 − 59 = 107 − 60 + (answer space) = (answer space)

Answer: 1, 48

  1. 107 − 60 = 47
  2. I took away 1 too many, so add it back: 47 + 1 = 48
9.153 − 5 = 153 − 3 − (answer space) = (answer space)

Answer: 2, 148

  1. 153 − 3 = 150 (back to a ten)
  2. 150 − 2 = 148
10.137 + 48 = 137 + 50 − (answer space) = (answer space)

Answer: 2, 185

  1. 137 + 50 = 187
  2. 187 − 2 = 185
11.178 − 98 = 178 − 100 + (answer space) = (answer space)

Answer: 2, 80

  1. 178 − 100 = 78
  2. I took away 2 too many, so add it back: 78 + 2 = 80
12.153 − 8 = 153 − 3 − (answer space) = (answer space)

Answer: 5, 145

  1. 153 − 3 = 150 (back to a ten)
  2. 150 − 5 = 145
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