Number
Rounding and estimation become formal, and the arithmetic of negatives and fractions has to be reliable.
- Round to a number of decimal places and to significant figures, and estimate calculations by rounding
- The four operations with negative numbers, fractions and mixed numbers
- Priority of operations including brackets, powers and roots
- Highest common factor, lowest common multiple and prime factorisation
- Rounding to decimal places and significant figures
- Percentages as multipliers, percentage change, and percentages over 100%
- Powers and roots, and standard form — which the sample framework places in Year 7 and Year 9 respectively
Estimate 48.7 × 6.2 by rounding.
About 50 × 6 = 300. The estimate is what tells you a calculator answer of 30.2 is wrong.
Where it usually goes wrong Significant figures. Children can apply the rule and still not know why 0.00456 to 2 s.f. is 0.0046 — the leading zeros do not count, and that needs explaining rather than practising.