Anytime you make concepts clear with role playing or hands-on experience, it's a win for the whole class. Ping-Pong balls are used to represent carbon in a carbon cycle role-play activity. In small groups, children first discuss what carbon is and how it moves through each of Earth's spheres. They show how carbon moves by drawing a card and acting out the movement of the carbon as described on the card. This is a great visual way to represent the carbon cycle!