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

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

1.158 + 48 = 158 + 50 − (answer space) = (answer space)

Answer: 2, 206

  1. 158 + 50 = 208
  2. 208 − 2 = 206
2.146 − 28 = 146 − 30 + (answer space) = (answer space)

Answer: 2, 118

  1. 146 − 30 = 116
  2. I took away 2 too many, so add it back: 116 + 2 = 118
3.131 − 2 = 131 − 1 − (answer space) = (answer space)

Answer: 1, 129

  1. 131 − 1 = 130 (back to a ten)
  2. 130 − 1 = 129
4.95 + 29 = 95 + 30 − (answer space) = (answer space)

Answer: 1, 124

  1. 95 + 30 = 125
  2. 125 − 1 = 124
5.66 − 38 = 66 − 40 + (answer space) = (answer space)

Answer: 2, 28

  1. 66 − 40 = 26
  2. I took away 2 too many, so add it back: 26 + 2 = 28
6.43 − 4 = 43 − 3 − (answer space) = (answer space)

Answer: 1, 39

  1. 43 − 3 = 40 (back to a ten)
  2. 40 − 1 = 39
7.28 + 19 = 28 + 20 − (answer space) = (answer space)

Answer: 1, 47

  1. 28 + 20 = 48
  2. 48 − 1 = 47
8.98 − 28 = 98 − 30 + (answer space) = (answer space)

Answer: 2, 70

  1. 98 − 30 = 68
  2. I took away 2 too many, so add it back: 68 + 2 = 70
9.124 − 6 = 124 − 4 − (answer space) = (answer space)

Answer: 2, 118

  1. 124 − 4 = 120 (back to a ten)
  2. 120 − 2 = 118
10.35 + 98 = 35 + 100 − (answer space) = (answer space)

Answer: 2, 133

  1. 35 + 100 = 135
  2. 135 − 2 = 133
11.37 − 9 = 37 − 10 + (answer space) = (answer space)

Answer: 1, 28

  1. 37 − 10 = 27
  2. I took away 1 too many, so add it back: 27 + 1 = 28
12.73 − 6 = 73 − 3 − (answer space) = (answer space)

Answer: 3, 67

  1. 73 − 3 = 70 (back to a ten)
  2. 70 − 3 = 67
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