Mathematics·Addition & Subtraction·meta
Checking Answers by Rounding
Use rounding to check answers to calculations and determine appropriate levels of accuracy in context
Suggested ages 9–10
Learning journey
Your child is mastering mental arithmetic with large numbers and using formal written methods for complex calculations, while learning to choose the most efficient method for different types of problems.
Evidence of understanding
- Check 47,832 + 23,156 ≈ 48,000 + 23,000 = 71,000 to verify the exact answer 70,988
- Decide whether to round to the nearest 100 or 1,000 for a given estimation context
- Identify that a calculated answer of 3,421 cannot be correct because the estimate gives approximately 50,000
Assessment prompt
If Checking Answers by Rounding gets an answer of 4,213 for an addition, can they round the numbers to double-check — like '4,000 + 1,000 ≈ 5,000' — and spot if the answer seems way off?
Standards alignment
No external standards are linked to this topic.