Mathematics·Addition & Subtraction·conceptual
Grouping numbers to add
Understand and apply the associative property of addition: when adding three numbers, any two can be added first
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 2 + 6 + 4 by first adding 6 + 4 = 10, then 2 + 10 = 12
- Explain that grouping addends differently gives the same total
- Choose which two numbers to add first to make the calculation easier
Assessment prompt
If Grouping numbers to add needs to add 3 + 7 + 6, can they spot that adding 3 and 7 first (to make 10) is easier — rather than always working left to right?
Standards alignment
1.OA.3US · ccss-math
Apply properties of operations
Common Core State Standards for Mathematics · 1