Children recap the key language of capacity and begin to estimate the capacity of different containers using non-standard units.
Fill it up
Provide children with sand/mud, various large containers and some smaller containers or utensils to use as non-standard measures, such as a large cup, a small cup, a ladle and a spoon. Challenge them to estimate how many of the large cups it would take to fill a container. Ask: Do you think it would take more or fewer small cups to fill the container? Encourage children to choose the most appropriate utensil for the container. Some children may be keen to record how many cups it takes to fill each container. Discuss what this tells them. Ask: How can you compare how much these containers hold using this way of filling them up? If one container takes 6 cups to fill it and another container takes 5 cups to fill it, which container holds more? Can you compare the containers if you used different-sized cups to fill them?
Encourage children to fill larger plant pots with soil and use smaller plant pots to fill a larger one. Ask: How many full small pots did it take to fill the large pot? Discuss what happens when they use a mix of different-sized small plant pots to fill the larger one.
Provide children with a variety of empty containers to use as boats, and sand, soil or small waterproof items such as counters to put into them. In the water area, encourage children to explore how full the boats can be before they sink. Ask: Can it float when it is empty? Can it float when it is nearly empty/half full? Does it still float when it is nearly full? Discuss what they find out. Ask: Do all the containers sink when they are full? Do all the containers float when they are empty/nearly empty?