## Compare the Cups

For this challenge, you will need lots of different cups. This picture shows some:

Which might you choose if you wanted a lot to drink? Why?

Which one would you choose if you did not want a lot to drink? Why?

Could you arrange the cups in a line from the one that holds the most liquid to the one that holds the least liquid?

How will you test whether you are right?

Photograph Acknowledgement

http://www.cupcompany.com/

#### Why do this problem?

This practical activity offers a context in which children can develop their conceptual understanding of capacity.

Possible approach

Although you could use the picture in the problem, it would be much better to have a collection of cups/glasses/mugs available for the children to explore themselves. You may want to offer a context for the activity to link in with a current theme or story.

Pose some questions orally to the group, as in the problem, and encourage them to think about the answers by estimating and by eye at first. You could discuss their thinking and then give them the opportunity to test out their ideas, perhaps with water or sand.

In the plenary, you could pose a final challenge, such as how many of the smallest cup will be needed to fill the largest cup? Again, encourage estimation first before trying it out practically.

#### Key questions

Tell me about your thinking.

How will you test out your ideas?

#### Possible extension

You could introduce a much, much smaller container, for example a spoon, and observe what the children do with it.

#### Possible support

Some learners might need help with awkward pouring.