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1st Grade Mental Addition and Subtraction Strategies Worksheet — Level 1 — Practice Set 4 — Answers

Answer sheet with worked solutions for the 1st Grade addition worksheet.

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Success TutoringWorksheetsAnswer sheet1st Grade · Mathematics · Addition

1st Grade Mental Addition and Subtraction Strategies Worksheet — Level 1 — Practice Set 4 — Answers

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

1.9 + 2 = 9 + 1 + (answer space) = (answer space)

Answer: 1, 11

  1. 9 + 1 = 10 (a ten)
  2. 10 + 1 = 11
2.8 + 9 = 8 + 2 + (answer space) = (answer space)

Answer: 7, 17

  1. 8 + 2 = 10 (a ten)
  2. 10 + 7 = 17
3.9 + 10 = (answer space) + (answer space) + 1 = (answer space)

Answer: 9, 9, 19

  1. Double 9 is 18
  2. 18 + 1 = 19
4.9 + 7 = 9 + 1 + (answer space) = (answer space)

Answer: 6, 16

  1. 9 + 1 = 10 (a ten)
  2. 10 + 6 = 16
5.9 + 5 = 9 + 1 + (answer space) = (answer space)

Answer: 4, 14

  1. 9 + 1 = 10 (a ten)
  2. 10 + 4 = 14
6.2 + 3 = (answer space) + (answer space) + 1 = (answer space)

Answer: 2, 2, 5

  1. Double 2 is 4
  2. 4 + 1 = 5
7.8 + 7 = 8 + 2 + (answer space) = (answer space)

Answer: 5, 15

  1. 8 + 2 = 10 (a ten)
  2. 10 + 5 = 15
8.9 + 6 = 9 + 1 + (answer space) = (answer space)

Answer: 5, 15

  1. 9 + 1 = 10 (a ten)
  2. 10 + 5 = 15
9.8 + 7 = (answer space) + (answer space) + 1 = (answer space)

Answer: 7, 7, 15

  1. Double 7 is 14
  2. 14 + 1 = 15
10.8 + 6 = 8 + 2 + (answer space) = (answer space)

Answer: 4, 14

  1. 8 + 2 = 10 (a ten)
  2. 10 + 4 = 14
11.6 + 5 = 6 + 4 + (answer space) = (answer space)

Answer: 1, 11

  1. 6 + 4 = 10 (a ten)
  2. 10 + 1 = 11
12.6 + 7 = (answer space) + (answer space) + 1 = (answer space)

Answer: 6, 6, 13

  1. Double 6 is 12
  2. 12 + 1 = 13
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