Suggestions for use: Go to 9:08 in the video. This activity may work best on a flat area of the playground. In pairs, pupils choose a container from a selection of containers where capacity is familiar, and fill with water (for example milk jugs, yogurt tubs, empty drinks bottles). They need to think carefully about the size of the puddle they predict the water will make once it is poured onto the playground. Encourage the pupils to give reasons for their estimations. Pupils then draw a chalk circle on the playground to record their estimation of the containers’ puddle size. Pupils investigate their estimate by pouring the water out of their chosen container, into their chalk circle, and compare the size of the puddle drawn with the actual puddle made (hence the flat ground; a good discussion point with the pupils). Tip: Use a large tub / baby’s bath tub with water to create a central location for the water). Use teacher questioning to activate pupils’ prior knowledge of estimation, capacity and volume.