Mathematics·Ratio & Proportion·representational
Bar Models for Ratios
Represent ratio and proportion problems using bar models (rectangular strips divided into equal parts labelled with quantities) and tape diagrams (segmented strips showing part-to-part and part-to-whole relationships); use these visual models to set up and solve unequal sharing, scaling, and percentage problems — drawing the diagram first, then reading off the answer
Suggested ages 9–12
Evidence of understanding
- Draw a bar model to represent a ratio problem — e.g. sharing £20 in the ratio 3:2 by drawing 5 equal blocks
- Use a bar model to solve a proportion problem and explain each step
- Compare bar models with other representations (tables, double number lines) and explain when each is most useful
Assessment prompt
If Bar Models for Ratios needs to share 30 stickers between two friends in a 2:3 ratio, can they draw a bar model — splitting a strip into 5 equal boxes — and use it to work out each share without just guessing?
Standards alignment
No external standards are linked to this topic.