This open-ended mathematics investigation has been designed to deepen students’ understanding of capacity.

Farmer Fred lives on a farm with his animals. To save water, Farmer Fred has decided that his animals must have a bath together. He needs a bath that will fit his dog, his pig, his goose and his goat, without the water overflowing. Farmer Fred doesn’t know if his idea is going to work, but he is too busy with all his jobs on the farm to test it.

In this investigation, the students must make decisions about capacity to explore whether it is possible for all of Farmer Fred’s animals to fit into one bathtub without the water overflowing. They must choose appropriate containers, design and build model animals using Plasticine, and then test their ideas.

Students are encouraged to record what happens during the investigation. If things don’t go to plan, they must adapt their ideas and try again!

This teaching resource includes:

• teacher notes, detailing a range of important information about the investigation
• a detailed description of the investigation for students, including step-by-step instructions
• various planning templates and recording worksheets
• reflection questions.