Mathematics·Addition & Subtraction·meta
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
Suggested ages 7–9
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
- 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
Assessment prompt
Before Estimating by rounding works out a calculation, can they make a sensible rough guess — and then check their answer using the opposite operation?
Standards alignment
Ma/KS2/Y3/AS/3GB · uk-nc-2013
Estimate and check answers
The national curriculum in England: Key stages 1 and 2 framework document · Key Stage 2
Ma/KS2/Y4/AS/2GB · uk-nc-2013
Estimate and check answers
The national curriculum in England: Key stages 1 and 2 framework document · Key Stage 2