Adding and subtracting tens mentally · seed 1 · A4, ink-friendly. The answer key prints on its own page for grown-ups.

Adding and Subtracting Tens Mentally

Mathematics · Addition & Subtraction · ages 6-7
Name ______________________   Date ____________

  1. 68 − 30 = ?

    • 38
    • 65
    • 98

  2. What is 82 - 40?

    Answer: ______________

  3. What is 20 + 30?

    • 60
    • 5
    • 50
    • 40

  4. 34 + 20 = ?

    • 36
    • 54
    • 44

  5. What is 54 + 20?

    Answer: ______________

  6. What is 38 + 40?

    • 68
    • 88
    • 70
    • 78

  7. What is 67 - 20?

    Answer: ______________

  8. Mia has 53 stickers. She gets 20 more stickers. How many does she have now?

    • 55
    • 73
    • 63

  9. Leo says 74 + 20 = 76. What mistake did he make?

    • He forgot to add anything
    • He added 20 twice
    • He added the 2 to the ones digit instead of the tens digit

  10. What is 91 - 60?

    • 31
    • 41
    • 30
    • 51
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Answer key

For grown-ups. Fold this page away before handing over the rest.

Adding and Subtracting Tens Mentally W1-mt_I5j1ZWo2cn-s1

  1. 38 · The ones digit 8 stays the same. The tens digit goes from 6 to 3, so 68 − 30 = 38.
  2. 42 · 82 minus 40 equals 42. Take 4 tens from 8 tens.
  3. 50 · 2 tens plus 3 tens is 5 tens, which is 50.
  4. 54 · The ones digit 4 stays the same. The tens digit goes from 3 to 5, so 34 + 20 = 54.
  5. 74 · 54 plus 20 equals 74.
  6. 78 · 3 tens plus 4 tens is 7 tens. With 8 ones that is 78.
  7. 47 · 67 minus 20 equals 47.
  8. 73 · The ones digit 3 does not change. The tens digit goes from 5 to 7, so Mia has 73 stickers.
  9. He added the 2 to the ones digit instead of the tens digit · Leo should add 2 tens, not 2 ones. The tens digit moves from 7 to 9, so 74 + 20 = 94.
  10. 31 · 9 tens take away 6 tens leaves 3 tens. With 1 one that is 31.
Worksheet · LightMySky