1. Direct proportion
N5.2 Core Starter
Orange drink is made by adding orange concentrate to water.
Which of A and B gives the stronger drink? Why?
Which of this pair gives the stronger drink? A B
Preamble
This whole-class discussion activity revisits some of the earlier work on ratio in the familiar context of the strength of a cordial drink. Give pupils some time to think about the two problems on their own before embarking on the class discussion.
As a supplementary problem, pupils could be asked how the strengths could most easily be made the same for each pair.
Should there be sufficient time, pupils could be invited to challenge the class with some similar problems (which they must be able to solve themselves).
Possible content
Comparing ratio.
Resources
None.
Solution/Notes
A is stronger than B. (Could be made equal by adding one more water to A.) C is stronger than D. (Could be made equal by adding one more orange to D.) D C