What you'll learn
Comparing quantities and working with rates.
Key skills
- Simplifying and dividing in a ratio.
- Direct and inverse proportion.
- Compound measures: speed = distance ÷ time, density = mass ÷ volume.
- Percentage change, simple and compound interest.
- Currency, best-buy and unit-cost problems.
Exam tips
- Find the value of 'one part' first in ratio problems.
- Use multipliers (e.g. × 1.05) for repeated percentage change.
Common mistakes
- Mixing up direct and inverse proportion.
- Forgetting to convert units (e.g. minutes to hours).