This is one of a series of educational games published in the early 20th century by Cincinnati Game Co. They were intended to be used for group play and class exercises in ways that would be fun for children as well as sound in terms of pedagogy. The deck is made up of 56 cards, each featuring a fraction with a denominator between 2 and 12. On 15 of the cards, the numerator is a "?", which can stand for any number less than the denominator. The rules booklet describes four group games and 13 class exercises. In the first game, for instance, the cards are dealt equally among the players, with any odd cards placed face up on the table. Play proceeds with each player turning over one card and by combining it with any other face-up cards, achieve a whole number. If successful, all the cards used are gathered up, and the player with the most cards at the end of the game wins.