Lesson 9 of 11
The big picture
Show on a big screenHere are the eight ideas, in order.
| Idea | Remember | Example |
|---|---|---|
| Out of a hundred | The second number is 100 | 9 of 20 → 45 of 100 |
| Three names | Divide, then × 100. Or write over 100 | 3/4 = 0.75 = 75% |
| Taking a percentage | Build it from 10% and 5%, or divide by 100 | 15% of 200 = 30 |
| Finding a percentage | Part over whole, then × 100 | 18 ÷ 24 = 75% |
| The base | A rise or fall is of the start | 250 up 20% = 300 |
| There and back | Two steps use two bases | 250 → 300 → 240 |
| Comparing fairly | Compare shares, not counts | 67.5% and 72% |
| Past a hundred | Name the whole first. The part can be bigger | 500 of 400 = 125% |
Your book's Part II, Chapter 1 is Fractions in Disguise. Go and open it. You already know the moves it asks for.