The note
How schools teach it now
Schools draw bar models: one box for each part of the ratio. For 2:3, draw 2 boxes and 3 boxes, find what one box is worth, then multiply. A ratio compares part to part; a fraction compares part to whole (2:3 means 2/5 and 3/5).
5-minute kitchen-table activity
Make squash: 1 part squash to 4 parts water. 'If we use 50 ml of squash, how much water? How much drink altogether?' (200 ml, 250 ml.) Then: 'For a 300 ml glass, how much squash?' (60 ml.)
Worked example
Sam and Priya share £45 in the ratio 2:3. How much does Priya get?
- Draw 2 boxes for Sam and 3 for Priya: 5 boxes altogether.
- One box is £45 ÷ 5 = £9.
- Priya has 3 boxes: 3 × £9 = £27.
Answer: £27 (and Sam gets £18)
Common mistakes to watch for
- Dividing by 2 or 3 instead of the total number of parts (5).
- Mixing up the order: 2:3 is not the same as 3:2.
- Treating 2:3 as the fraction 2/3.
Encouragement
- Try saying
- “Let's draw the boxes and find what one box is worth.”
- Rather than
- “Ratio is just a harder kind of fraction.”