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3rd Grade Mental Addition and Subtraction Strategies Worksheet — Level 3 — Answers

Answer sheet with worked solutions for the 3rd Grade addition worksheet.

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Success TutoringWorksheetsAnswer sheet3rd Grade · Mathematics · Addition

3rd Grade Mental Addition and Subtraction Strategies Worksheet — Level 3 — Answers

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

1.160 + 59 = 160 + 60 − (answer space) = (answer space)

Answer: 1, 219

  1. 160 + 60 = 220
  2. 220 − 1 = 219
2.90 − 19 = 90 − 20 + (answer space) = (answer space)

Answer: 1, 71

  1. 90 − 20 = 70
  2. I took away 1 too many, so add it back: 70 + 1 = 71
3.172 − 5 = 172 − 2 − (answer space) = (answer space)

Answer: 3, 167

  1. 172 − 2 = 170 (back to a ten)
  2. 170 − 3 = 167
4.197 + 48 = 197 + 50 − (answer space) = (answer space)

Answer: 2, 245

  1. 197 + 50 = 247
  2. 247 − 2 = 245
5.154 − 48 = 154 − 50 + (answer space) = (answer space)

Answer: 2, 106

  1. 154 − 50 = 104
  2. I took away 2 too many, so add it back: 104 + 2 = 106
6.84 − 9 = 84 − 4 − (answer space) = (answer space)

Answer: 5, 75

  1. 84 − 4 = 80 (back to a ten)
  2. 80 − 5 = 75
7.51 + 98 = 51 + 100 − (answer space) = (answer space)

Answer: 2, 149

  1. 51 + 100 = 151
  2. 151 − 2 = 149
8.62 − 49 = 62 − 50 + (answer space) = (answer space)

Answer: 1, 13

  1. 62 − 50 = 12
  2. I took away 1 too many, so add it back: 12 + 1 = 13
9.143 − 6 = 143 − 3 − (answer space) = (answer space)

Answer: 3, 137

  1. 143 − 3 = 140 (back to a ten)
  2. 140 − 3 = 137
10.42 + 28 = 42 + 30 − (answer space) = (answer space)

Answer: 2, 70

  1. 42 + 30 = 72
  2. 72 − 2 = 70
11.96 − 48 = 96 − 50 + (answer space) = (answer space)

Answer: 2, 48

  1. 96 − 50 = 46
  2. I took away 2 too many, so add it back: 46 + 2 = 48
12.32 − 8 = 32 − 2 − (answer space) = (answer space)

Answer: 6, 24

  1. 32 − 2 = 30 (back to a ten)
  2. 30 − 6 = 24
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