⭐ 1st Grade · Free printable

Missing Number Subtraction Worksheets

In these problems the starting number is missing: "something minus 5 is 4." Children cannot just count back, so they have to think about what subtraction means.

The key idea is that addition undoes subtraction. If you took 5 away and have 4 left, you started with 4 + 5 = 9. Understanding this relationship makes both operations easier.

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Choose how many problems. Every worksheet has new problems and a matching answer key.

Opens in a new tab, ready to print. Use the Answer Key button there to print the answers.

Sample problems

  1. __ − 8 = 10
  2. __ − 8 = 5
  3. __ − 6 = 8
  4. __ − 7 = 5
  5. __ − 3 = 8
  6. __ − 3 = 10
  7. __ − 10 = 2
  8. __ − 9 = 10

Worked example

__ − 10 = 7

  1. Think: I took 10 away and had 7 left. How many did I start with?
  2. Put back the 10 that was taken away: 7 + 10 = 17.
  3. The missing number is 17.
  4. Check: 17 − 10 = 7. ✓

Common mistakes

  • Subtracting the two numbers that are shown. For __ − 10 = 7, a child may write 3 (10 − 7). Plugging the answer back in (3 − 10 = 7?) shows that it does not work.
  • Writing one of the given numbers in the blank. Always check by reading the whole sentence with the answer filled in.

Tips for practicing at home

  • Tell it as a story: "I had some cookies, ate 5, and have 4 left. How many did I have?"
  • Use fact family triangles to show 4 + 5 = 9 and 9 − 5 = 4 together.
  • Make checking a routine: read the problem aloud with the answer filled in.

Common Core standards

1.OA.D.8
Determine the unknown whole number in an addition or subtraction equation relating three whole numbers.
1.OA.B.4
Understand subtraction as an unknown-addend problem.

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