Subtraction as an Unknown Addend Activity
This subtraction as an unknown addend activity helps K through 2nd grade students solve subtraction within 20 by matching each fact to its addition fact card. Answer key included.
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About this resource
Description
This subtraction as an unknown addend activity shows children that every subtraction fact has an addition fact hiding inside it. When students see that 10 − 8 and 8 + ? = 10 share the same missing number, they can use the addition facts they already know to solve subtraction within 20.
The printable game includes 12 equation cards and 12 answer cards. Each equation card shows a subtraction fact and its matching addition fact, and children find the one answer card that completes both. They match the cards, then write each missing number on the Recording Sheet. Use it in a math center, with a partner, in a small group or as a whole class game.
What’s Included
- Colorful cover page
- How to Use page with prep tips, game steps and extension ideas
- 12 equation cards and 12 answer cards (cut sheets)
- Recording Sheet
- 1st grade practice worksheet: use the addition fact to solve the subtraction fact
- Game answer key and practice worksheet answer key
Why Kids Love It
- Matching cards turns fact practice into a hands-on game.
- Every equation card fits exactly one answer card, so children can check their own thinking.
- Seeing addition and subtraction side by side builds number sense and fact fluency.
Ideas for Teachers and Parents
This kindergarten addition activity also works for first and second grade review. Start with the cards whose missing numbers are under ten, then add the rest. Ask children to say the whole fact family out loud for each card, or have partners race to match all twelve cards. For extra challenge, students can write a new card with their own fact. Pair the subtraction as an unknown addend activity with the practice worksheet for homework or a quick check.
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