Edexcel IGCSE Maths 复习笔记 1.11.1 Ratios
What is a ratio?
- A ratio is a way of comparing one part of a whole to another
- A ratio can also be expressed as a fraction (of the whole)
- We often use a ratio (instead of a fraction) when we are trying to show how things are shared out or in any situation where we might use scale factors
How to work with ratios
- Put what you know in RATIO form (use more than one line if necessary)
- Add “extra bits” (eg Total, Difference, Sum) if you think they might be useful
- Use SCALE FACTORS to complete lines
- Pick out the ANSWER!
One less obvious place to use Ratios is when dealing with Currency Conversion problems – see Exchange Rates.