Grade 1 · Math · Addition

1st Grade Missing Addends Within 20 worksheets

6 printable versionsChallenge MeAbout 9 minutes eachFree · no account

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Missing Addends Within 20

Grade 1 Math Worksheet - Challenge Me

NameDate

Write the answer on the line.

Fill the blank: + 8 = 20.
8 is made from 4 and what number?
What number completes 9 + = 17?
What number completes 12 + = 15?
What number completes 2 + = 9?
15 is made from 8 and what number?
What number completes 10 + = 16?
Fill the blank: + 8 = 10.
Fill the blank: + 5 = 13.
What number completes 1 + = 11?

1st Grade Missing Addends Within 20 worksheet 1 – printable PDF — Download PDF: 1 2 3 4 5 6

About this worksheet

Missing Addends Within 20 gives grade 1 students a focused page for a skill that parents and teachers often need as its own printable worksheet. Missing addends are a small, searchable math need that broad addition pages often hide. Students may solve 8 + 5 but freeze when the blank appears before or after the equal sign. The items rotate through several question types so the page is not just the same prompt with different numbers or words. Students find unknown addends, use related subtraction, and check whether both sides of an equation match.

Support versions keep the reading load, numbers, or choices friendlier while preserving the same thinking. Standard versions match everyday classroom practice. Challenge versions add a closer distractor, an extra reasoning step, or less familiar examples. Before answering, students should say what the question is asking, point to the evidence, and check that the answer fits the exact skill named in the title.

What your child will learn

Find a missing part
Use addition and subtraction together
Check equations within 20

Common Core standard: 1.OA.D.8

Worked example

In 8 + blank = 13, count from 8 to 13 or subtract 13 - 8 to get 5.

Common mistake

Adding all visible numbers instead of finding the missing part.

Helpful hint

Ask what part is missing from the whole.

Questions parents ask

What is the most common mistake with missing addends within 20?

Adding all visible numbers instead of finding the missing part.

How can I help my child with missing addends within 20?

Ask what part is missing from the whole.

Are these 1st grade math worksheets free to print?

Yes. All 6 printable versions on this page are free to download and print, with no account needed.

More 1st grade addition

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