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Year 4 Mental Addition and Subtraction Strategies Worksheet — Level 3 — Practice Set 2 — 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 — Practice Set 2 — Answers

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

1.45 + 98 = 45 + 100 − (answer space) = (answer space)

Answer: 2, 143

  1. 45 + 100 = 145
  2. 145 − 2 = 143
2.88 − 19 = 88 − 20 + (answer space) = (answer space)

Answer: 1, 69

  1. 88 − 20 = 68
  2. I took away 1 too many, so add it back: 68 + 1 = 69
3.23 − 9 = 23 − 3 − (answer space) = (answer space)

Answer: 6, 14

  1. 23 − 3 = 20 (back to a ten)
  2. 20 − 6 = 14
4.161 + 28 = 161 + 30 − (answer space) = (answer space)

Answer: 2, 189

  1. 161 + 30 = 191
  2. 191 − 2 = 189
5.59 − 38 = 59 − 40 + (answer space) = (answer space)

Answer: 2, 21

  1. 59 − 40 = 19
  2. I took away 2 too many, so add it back: 19 + 2 = 21
6.22 − 5 = 22 − 2 − (answer space) = (answer space)

Answer: 3, 17

  1. 22 − 2 = 20 (back to a ten)
  2. 20 − 3 = 17
7.149 + 18 = 149 + 20 − (answer space) = (answer space)

Answer: 2, 167

  1. 149 + 20 = 169
  2. 169 − 2 = 167
8.67 − 28 = 67 − 30 + (answer space) = (answer space)

Answer: 2, 39

  1. 67 − 30 = 37
  2. I took away 2 too many, so add it back: 37 + 2 = 39
9.181 − 9 = 181 − 1 − (answer space) = (answer space)

Answer: 8, 172

  1. 181 − 1 = 180 (back to a ten)
  2. 180 − 8 = 172
10.169 + 98 = 169 + 100 − (answer space) = (answer space)

Answer: 2, 267

  1. 169 + 100 = 269
  2. 269 − 2 = 267
11.82 − 59 = 82 − 60 + (answer space) = (answer space)

Answer: 1, 23

  1. 82 − 60 = 22
  2. I took away 1 too many, so add it back: 22 + 1 = 23
12.151 − 3 = 151 − 1 − (answer space) = (answer space)

Answer: 2, 148

  1. 151 − 1 = 150 (back to a ten)
  2. 150 − 2 = 148
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