Children can hear their own heartbeat with this stethoscope. This will help them understand how their bodies work. Why not contrast the speed of the heart before and after physical activity.
ELG: Understanding The World: children know about similarities and differences in relation to places, objects, materials and living things. They talk about the features of their own immediate environment and how environments might vary from one another. They make observations of animals and plants and explain why some things occur, and talk about changes.