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Math Grade K-1 Answer Key

Addition Within 20

Practice adding numbers up to 20

Answer Key
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Addition Within 20

Practice adding numbers up to 20

Math - Grade K-1

Instructions: Read each problem carefully and solve the addition sentence. Show your work if needed.
  1. 1

    Solve: 3 + 4 = __

    Count on 4 more starting at 3.

    The sum of 3 and 4 is 7.
  2. 2

    Solve: 6 + 2 = __

    The sum of 6 and 2 is 8.
  3. 3

    Solve: 5 + 5 = __

    This is a doubles fact.

    The sum of 5 and 5 is 10.
  4. 4

    Solve: 7 + 3 = __

    The sum of 7 and 3 is 10.
  5. 5

    Solve: 9 + 1 = __

    Adding 1 gives the next number.

    The sum of 9 and 1 is 10.
  6. 6

    Solve: 8 + 4 = __

    The sum of 8 and 4 is 12.
  7. 7

    Solve: 10 + 6 = __

    Start at 10 and count on 6 more.

    The sum of 10 and 6 is 16.
  8. 8

    Solve: 11 + 3 = __

    The sum of 11 and 3 is 14.
  9. 9

    Solve: 12 + 5 = __

    Count on 5 more from 12.

    The sum of 12 and 5 is 17.
  10. 10

    Solve: 14 + 2 = __

    The sum of 14 and 2 is 16.
  11. 11

    Solve: 7 + 8 = __

    You can think of 7 + 7 = 14, then add 1 more.

    The sum of 7 and 8 is 15.
  12. 12

    Solve: 9 + 9 = __

    The sum of 9 and 9 is 18.
LivePhysics.com Math - Grade K-1 - Answer Key