Finding a missing number in addition
Understand subtraction as finding an unknown addend (e.g. 10 − 8 = ? is the same as 8 + ? = 10)
Teaching approaches
Gakuva’s recommended starting approach is selected. You can still compare every option.
1 approach
Can your child see that '10 − 8 = ?' is the same as asking 'what do I add to 8 to reach 10?' — so they can use their adding knowledge to help with subtraction?
Understand subtraction as finding an unknown addend (e.g. 10 − 8 = ? is the same as 8 + ? = 10)
Learning resources
Reviewed external links that reinforce this concept. They do not replace Gakuva’s teaching approach.
Hit the Button · Number Bonds
Find the missing partner in a bond—the same skill as a missing addend. Choose Number Bonds and an appropriate total.
Proof: Save a Number Bonds screenshot and a parent note of two missing-number equations solved (for example 7 + ___ = 10).
Addition & Subtraction Facts
Supplemental visual for relating a whole and parts when one addend is unknown. Cover one part and ask what is missing.
Proof: Save a screenshot and a parent note of a missing-addend question answered from the model.
Explore the learning path
2 before · 1 after
Before
This concept
Check understanding
- Solve 10 − 8 by thinking 'what do I add to 8 to make 10?'
- Explain that subtraction can be thought of as a missing-addend problem
- Use known addition facts to solve related subtraction problems
“Can your child see that '10 − 8 = ?' is the same as asking 'what do I add to 8 to reach 10?' — so they can use their adding knowledge to help with subtraction?”
Curriculum record
- Type
- Conceptual
- Subject
- Mathematics
- Domain
- Addition & Subtraction
- Age range
- Ages 6–7
Standards