Game Theory: Race to 15 (for Kindergarten, but also for 1-6)

Since Magic Squares are a little too advanced for most kindergarteners, I developed a lesson using game theory. The rules for Race to 15 are as follows:

• there are 9 cards numbered 1-9 (you can use the ace, 2, 3, 4, 5, 6, 7, 8 and 9 from a deck of cards or you can cut out the numbers 1-9 below).

• place the 9 cards face up.

• 2 players take turns picking up cards one at a time until one player has 3 cards that add up to exactly 15. 

• the player with exactly three cards that add up to 15 has won the game (two, four, or five cards that add up to 15 will not win; getting three cards that add up to more than 15 also will not win).

• is it possible for two good players to ever have a winner?

The attached pdf entitled Game Theory: Race to 15 contains the rules as well as 9 cards that can be cut out to play the game.

We also used the second page of that pdf with 3 x 3 grids to have the children write down the numbers 1-9 in random order. Then I had the children practice adding each row, column and both diagonals. These are 8 separate sums. They can try this many different ways. If they are feeling ambitious, they should write down the numbers 1-16 in the 4 x 4 grid and 1-25 in the 5 x 5 grid. Then they should add up each row (horizontally), each column (vertical), and both diagonals.