We describe a mathematics computer game for children designed to promote causal reasoning, choice-making, and other higher-order cognitive activities. The game consists of a choice-based board game, enhanced with a conversational, teachable agent, taught to play the game, by the child, through demonstrations and questions. Game design is motivated by causal reasoning theory and educational psychology. The game is currently evaluated in an ongoing large-scale study that seeks to investigate the game’s effects on the players’ abilities to reason and make productive choices. The study involves 20 elementary-school classes at different levels.