There are 24 cubes with numbers and other mathematical symbols on the sides in the box. From the box cover: Divide the cubes between 2-4 players who then proceed to construct their own separate sum (all cubes must be used) as example below:- 9x9=81 A player on completion of sum may call sumfun when all play must stop. Answers of completed (and correct) sums count as score. Redeal and play up to five games for set.