Estimating by rounding
Estimate the answer to a calculation and use inverse operations to check answers; apply to increasingly large numbers using rounding and inverse reasoning
Teaching approaches
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1 approach
Before your child works out a calculation, can they make a sensible rough guess — and then check their answer using the opposite operation?
Estimate the answer to a calculation and use inverse operations to check answers; apply to increasingly large numbers using rounding and inverse reasoning
Learning resources
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This concept
Check understanding
- Round numbers to the nearest 10 or 100 to estimate a sum or difference before calculating
- Use addition to check a subtraction answer, or vice versa
- Identify when a calculated answer is unreasonable based on the estimate
- Round numbers to estimate a sum or difference before calculating
- Use addition to check a subtraction answer and vice versa
- Identify an unreasonable answer by comparing to the estimate
“Before your child works out a calculation, can they make a sensible rough guess — and then check their answer using the opposite operation?”
Curriculum record
- Type
- Meta
- Subject
- Mathematics
- Domain
- Addition & Subtraction
- Age range
- Ages 7–9
Standards