The Challenge prompts the children to investigate the idea that different containers can hold different amounts of liquid. Provide containers of different sizes and shapes and challenge the children to estimate which holds the most or least, similar to the picture, before finding out which holds the most water or sand by pouring the water from one container into another and discussing what it means if it overflows.
Provide sets of different-sized containers (labelled in some way) for children to describe and order. Encourage them to find out which container holds the most by filling the containers with water and pouring them from one to another. Make sure some of the containers hold the same amount. Children then put the containers in order, from the one that holds the most to the one that holds the least.