Ratios and rates

What they’re learning

Your child is learning that ratios compare quantities and rates compare quantities with different units. They use equivalent ratios to reason about scaling.

Explain it to my child

A ratio of 2 red beads to 3 blue beads means that for every group of 2 red, there are 3 blue. If the pattern doubles, 4 red goes with 6 blue.

Try it together

Make a drink mix or pretend recipe ratio such as 1 scoop syrup to 4 scoops water. Scale it up for 2 or 3 batches and talk about what must stay proportional.

Practice

1. Ratio 2:5 doubled becomes?
2. If 3 apples cost $6, what is the cost per apple?
3. A recipe uses 1 cup rice to 2 cups water. Water for 3 cups rice?
4. Which is equivalent to 4:6: 2:3 or 3:4?
5. A car travels 120 km in 2 hours. Average rate?

Check understanding

• Can your child distinguish a ratio from a total?
• Can they scale both parts of a ratio by the same factor?