The box contains two dices with ratios on their faces, several coloured sectors of disk; and rings which you can clip the sectors onto. The different proportions used are : 1/2 ; 1/3 ;1/4 ; 1/6 and 1/8. At his turn, each player throws the two ratio dices and picks up the disks sectors accordingly to the results. Then he tries to arrange those sectors around his rings, in order to form two perfect circles, and wins if he succeeds in this task. Otherwise, the winner is he who has the most rings completes, or else the most sectors. Three different variants of growing difficulties are proposed, allowing players to make use of different levels of math abilities from adding fractions to basic probabilities.