At the end of each unit, a summative task is designed to assess each student's understanding of the central idea. For this summative, the children worked individually to paint a river and salmon. They were asked the following set of questions relating to the central idea: What do you know about water? Why is water important to people? (what do they use it for) Why is water important to animals? Why is water important to plants? What would happen if there was no water? How can we make sure this never happens; how can we save water?