Mathematics·Addition & Subtraction·procedural
Unknown in Addition & Subtraction
Determine the unknown whole number in an addition or subtraction equation relating three whole numbers
Suggested ages 6–7
Learning journey
Your child is building strong foundations in addition and subtraction — learning to add and subtract numbers fluently within 20, understanding the relationship between these operations, and applying various mental strategies to solve problems.
Evidence of understanding
- Solve 8 + ? = 11 and write 3
- Solve 5 = □ − 3 and write 8
- Solve 6 + 6 = □ and write 12
Assessment prompt
If Unknown in Addition & Subtraction sees '? + 6 = 14' or '9 − ? = 4' written on paper, can they figure out what number goes in the gap?
Standards alignment
1.OA.8US · ccss-math
Determine unknown whole number
Common Core State Standards for Mathematics · 1