Mathematics·Addition & Subtraction·meta
Addition and subtraction strategies (age 7+)
Explain why addition and subtraction strategies work, using place value and the properties of operations
Suggested ages 7–8
Learning journey
Your child is advancing their calculation skills — learning to add and subtract larger numbers up to 1000, mastering mental math strategies, and solving more complex word problems.
Evidence of understanding
- Explain why adding tens and ones separately gives the correct total
- Describe why a compensation strategy works (e.g. 'I added 1 too many, so I subtract 1')
- Use place-value language to justify a written method step by step
Assessment prompt
If Addition and subtraction strategies (age 7+) works out '67 + 24' by splitting it into '60 + 20' and '7 + 4', can they explain to you in words *why* that approach gives the right answer?
Standards alignment
2.NBT.9US · ccss-math
Explain addition and subtraction strategies
Common Core State Standards for Mathematics · 2