Number one hits the balloon up, calls out the number of another player who must come and play the balloon high, calling out another number etc.
The player who hits the balloon must change places with the player whose name he called out.
"It is not only useful for staff who are experienced but a valuable tool for those subject staff who have to take teams."
The variety of sessions across sports - sometimes we steal session ideas from one sport and use them with another.
As we enter the business end of the competition, we take a look at the remaining eight teams and the key talking points surrounding each side.