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

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

1.44 + 19 = 44 + 20 − (answer space) = (answer space)

Answer: 1, 63

  1. 44 + 20 = 64
  2. 64 − 1 = 63
2.104 − 39 = 104 − 40 + (answer space) = (answer space)

Answer: 1, 65

  1. 104 − 40 = 64
  2. I took away 1 too many, so add it back: 64 + 1 = 65
3.81 − 2 = 81 − 1 − (answer space) = (answer space)

Answer: 1, 79

  1. 81 − 1 = 80 (back to a ten)
  2. 80 − 1 = 79
4.116 + 48 = 116 + 50 − (answer space) = (answer space)

Answer: 2, 164

  1. 116 + 50 = 166
  2. 166 − 2 = 164
5.133 − 98 = 133 − 100 + (answer space) = (answer space)

Answer: 2, 35

  1. 133 − 100 = 33
  2. I took away 2 too many, so add it back: 33 + 2 = 35
6.184 − 6 = 184 − 4 − (answer space) = (answer space)

Answer: 2, 178

  1. 184 − 4 = 180 (back to a ten)
  2. 180 − 2 = 178
7.164 + 9 = 164 + 10 − (answer space) = (answer space)

Answer: 1, 173

  1. 164 + 10 = 174
  2. 174 − 1 = 173
8.120 − 29 = 120 − 30 + (answer space) = (answer space)

Answer: 1, 91

  1. 120 − 30 = 90
  2. I took away 1 too many, so add it back: 90 + 1 = 91
9.84 − 5 = 84 − 4 − (answer space) = (answer space)

Answer: 1, 79

  1. 84 − 4 = 80 (back to a ten)
  2. 80 − 1 = 79
10.98 + 39 = 98 + 40 − (answer space) = (answer space)

Answer: 1, 137

  1. 98 + 40 = 138
  2. 138 − 1 = 137
11.61 − 19 = 61 − 20 + (answer space) = (answer space)

Answer: 1, 42

  1. 61 − 20 = 41
  2. I took away 1 too many, so add it back: 41 + 1 = 42
12.71 − 6 = 71 − 1 − (answer space) = (answer space)

Answer: 5, 65

  1. 71 − 1 = 70 (back to a ten)
  2. 70 − 5 = 65
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