Mathematics Multiplication & Division Meta 10–11 yrs

Estimation to check answers to calculations

估算验证计算结果

Description

Use estimation to check answers to calculations and determine, in the context of a problem, an appropriate degree of accuracy

Mastery Evidence

✓ Estimate 487 × 23 by rounding to 500 × 20 and use this to check a calculated answer
✓ Determine whether an exact answer or an estimate is more appropriate in a given context
✓ Spot an unreasonable answer by comparing with a quick mental estimate

Assessment Prompt

Before your child works out a large multiplication or division, can they estimate what the answer should be roughly — and then check whether their final answer is in the right ballpark?