Each player has a stack of green cards face down in front of him. The 18 yellow cards with the numbers are placed in the center of the table. In his turn player turns a card face-up and reads an enigma. The other players must hit as fast as possible on the number they think is the right answer. The fastest receives the "enigma" card. When all the "enigma" cards have been given, each player counts the number of cards he has won. The winner is the one with the most cards. There are 340 simple mathematical problems, divided into 3 categories : "French language and numbers", "Mathematical language" and "Operations".