This unit was taught to a fifth-grade class. The students have already learned about matter and the different states of matter. The goal of this unit is for students to understand the movement of matter among the producers, consumers, decomposers and how the matter recycles back to start the cycle again by providing much-needed nutrients. The students see the movement by seeing how energy transfers from the sun to the producers and decreases as it moves up the food chain. They also see the major role decomposers have in an ecosystem.