Each player should have 8 index cards. On each of the index cards, each player will draw a matrix. The dimensions of the eight matrices will be 2 × 3, 3 × 2, 2 × 2, 3 × 3, 2 × 4, 4 × 2, 3 × 4 and 4 × 3. The numbers used in the matrix may be any integers between and including -12 and 12. Next, place all of the cards together. Shuffle and place them face down in a rectangular array on the table.

Player 1 begins by turning over two cards. If the two cards can be added, player 1 keeps the two cards and turns over two more cards. If the two cards cannot be added, player 1 turns the two cards back over and player 2 turns over two cards. Play continues around until all cards have been matched and collected. Each player then uses scratch paper to find the sum of each pair. Players exchange papers, check each other's work, and award 1 point for each correct sum. The player with the most points wins.