6 progressive games. The child begins by counting the elements of a card, then he looks for the missing number of the operation, and then the result of the addition. The cards are self-correcting. Children also play lotto-memo with several people, to pose additions and subtractions with the number tokens. Calculation becomes familiar and the logic of calculation progresses, through play. 6 progressive games. The child begins by counting the elements of a card, then he looks for the missing number of the operation, and then the result of the addition. The cards are self-correcting. Children also play lotto-memo with several people, to pose additions and subtractions with the number tokens. With the early school, calculation becomes familiar and the logic of calculation progresses, through play.