Abstract: A device for developing and also determining the ability of a child or adult in solving a logical problem; the device in its most elementary form consisting of a closed rectangular box having a transparent front side to allow observation inside, the box having an opening near a pair of diagonally opposite corners so a reward such as a candy or the like is dropped through one of the openings into the box interior after which the opening is closed, and a player then attempts to shake the reward out of the other opening in a minimum time and claim the reward.