You will need:
A ball for everyone involved.
All students stand in a circle. The students are in pairs with the one facing the circle. Good idea to take a round where the pairs are mentioned so everyone is aware of who they are with.
Everyone counts down – 3-2-1-now. For now, all the pairs need to throw to each other. Can the whole group (class) succeed in catching all the balls?
Playing can make it easier if each pair has only one ball.