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

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

1.153 + 48 = 153 + 50 − (answer space) = (answer space)

Answer: 2, 201

  1. 153 + 50 = 203
  2. 203 − 2 = 201
2.124 − 19 = 124 − 20 + (answer space) = (answer space)

Answer: 1, 105

  1. 124 − 20 = 104
  2. I took away 1 too many, so add it back: 104 + 1 = 105
3.61 − 7 = 61 − 1 − (answer space) = (answer space)

Answer: 6, 54

  1. 61 − 1 = 60 (back to a ten)
  2. 60 − 6 = 54
4.102 + 39 = 102 + 40 − (answer space) = (answer space)

Answer: 1, 141

  1. 102 + 40 = 142
  2. 142 − 1 = 141
5.20 − 9 = 20 − 10 + (answer space) = (answer space)

Answer: 1, 11

  1. 20 − 10 = 10
  2. I took away 1 too many, so add it back: 10 + 1 = 11
6.42 − 6 = 42 − 2 − (answer space) = (answer space)

Answer: 4, 36

  1. 42 − 2 = 40 (back to a ten)
  2. 40 − 4 = 36
7.58 + 29 = 58 + 30 − (answer space) = (answer space)

Answer: 1, 87

  1. 58 + 30 = 88
  2. 88 − 1 = 87
8.74 − 19 = 74 − 20 + (answer space) = (answer space)

Answer: 1, 55

  1. 74 − 20 = 54
  2. I took away 1 too many, so add it back: 54 + 1 = 55
9.72 − 4 = 72 − 2 − (answer space) = (answer space)

Answer: 2, 68

  1. 72 − 2 = 70 (back to a ten)
  2. 70 − 2 = 68
10.32 + 48 = 32 + 50 − (answer space) = (answer space)

Answer: 2, 80

  1. 32 + 50 = 82
  2. 82 − 2 = 80
11.75 − 29 = 75 − 30 + (answer space) = (answer space)

Answer: 1, 46

  1. 75 − 30 = 45
  2. I took away 1 too many, so add it back: 45 + 1 = 46
12.24 − 5 = 24 − 4 − (answer space) = (answer space)

Answer: 1, 19

  1. 24 − 4 = 20 (back to a ten)
  2. 20 − 1 = 19
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