The Number topic covers integers, fractions, decimals, percentages, ratio, indices, standard form, and factors and multiples.
Key skills: find a percentage of a quantity (15% of 200 = 30); simplify ratios (10 : 15 = 2 : 3); use the HCF and LCM; and write numbers in standard form $A \times 10^n$ with $1 \le A \lt 10$.
Remember
- Percentage of a quantity = (percent ÷ 100) × quantity.
- Standard form: $A \times 10^n$, $1 \le A \lt 10$.