This is a game for two players (or a class split into two teams).
Take it in turns to choose one of the numbers 1 to 9. It is now your number and your opponent cannot choose it. Each number can be chosen only once.
To win, be the first to pick 3 numbers that add up to 15.
The game may end in a draw if all the numbers have been chosen and nobody can make 15.
Resources: Number cards with numbers 1 to 9.