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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.

1.31 + 18 = 31 + 20 − (answer space) = (answer space)

Answer: 2, 49

  1. 31 + 20 = 51
  2. 51 − 2 = 49
2.73 − 18 = 73 − 20 + (answer space) = (answer space)

Answer: 2, 55

  1. 73 − 20 = 53
  2. I took away 2 too many, so add it back: 53 + 2 = 55
3.103 − 6 = 103 − 3 − (answer space) = (answer space)

Answer: 3, 97

  1. 103 − 3 = 100 (back to a ten)
  2. 100 − 3 = 97
4.96 + 39 = 96 + 40 − (answer space) = (answer space)

Answer: 1, 135

  1. 96 + 40 = 136
  2. 136 − 1 = 135
5.97 − 18 = 97 − 20 + (answer space) = (answer space)

Answer: 2, 79

  1. 97 − 20 = 77
  2. I took away 2 too many, so add it back: 77 + 2 = 79
6.53 − 6 = 53 − 3 − (answer space) = (answer space)

Answer: 3, 47

  1. 53 − 3 = 50 (back to a ten)
  2. 50 − 3 = 47
7.193 + 29 = 193 + 30 − (answer space) = (answer space)

Answer: 1, 222

  1. 193 + 30 = 223
  2. 223 − 1 = 222
8.134 − 99 = 134 − 100 + (answer space) = (answer space)

Answer: 1, 35

  1. 134 − 100 = 34
  2. I took away 1 too many, so add it back: 34 + 1 = 35
9.144 − 8 = 144 − 4 − (answer space) = (answer space)

Answer: 4, 136

  1. 144 − 4 = 140 (back to a ten)
  2. 140 − 4 = 136
10.142 + 9 = 142 + 10 − (answer space) = (answer space)

Answer: 1, 151

  1. 142 + 10 = 152
  2. 152 − 1 = 151
11.143 − 39 = 143 − 40 + (answer space) = (answer space)

Answer: 1, 104

  1. 143 − 40 = 103
  2. I took away 1 too many, so add it back: 103 + 1 = 104
12.103 − 9 = 103 − 3 − (answer space) = (answer space)

Answer: 6, 94

  1. 103 − 3 = 100 (back to a ten)
  2. 100 − 6 = 94
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