🌱 Kindergarten · Free printable

Missing Number Addition Worksheets

Missing number problems ask a different question: "3 plus what makes 7?" Instead of finding a total, children find one of the parts. It teaches that numbers can be broken apart in different ways, which is the start of algebra thinking.

Kindergartners do this with number bonds and objects. First graders meet it formally as "finding the unknown number" (1.OA.D.8), so this is great preparation. Every total here is 10 or less.

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Sample problems

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

Worked example

6 + __ = 10

  1. Read it as "6 plus what makes 10?"
  2. Start at 6 and count up to 10, putting up a finger for each number: 7, 8, 9, 10.
  3. You put up 4 fingers, so the missing number is 4.
  4. Check: 6 + 4 = 10. ✓

Common mistakes

  • Adding the two numbers that are shown. For 6 + __ = 10, a child may write 16. Reading the problem aloud as a question ("6 plus what makes 10?") helps.
  • Writing the total in the blank. If the answer written is 10, the child is copying the total. Ask them to check: does 6 + 10 really make 10?

Tips for practicing at home

  • Play hide-and-seek counters: show 7 counters, hide some under a cup, and show the 3 still out. How many are hiding?
  • Draw number bonds: a circle with the total, joined to two circles with the parts.
  • Ask everyday "how many more" questions: "We need 5 plates and have 2 out. How many more?"

Common Core standards

K.OA.A.3
Decompose numbers less than or equal to 10 into pairs in more than one way.
K.OA.A.4
For any number from 1 to 9, find the number that makes 10 when added to it.

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