rithmomachia

Rithmomachia is a two-player board game invented in the middle ages. Medieval scholars used this game to help students learn grade-school arithmetic since the (cleverly designed) rules governing the rithmomachia pieces are intertwined with the rules for integer arithmetic. Not only did this teach logical reasoning but the sacred geometry and number theory associated with the pieces taught them spiritual reasoning.
Hit "?" for help on screen.
Below, there is a step-by-step pdf guide (rithmo-web_getting-started-tutorial..pdf) using screenshots of the buttons and game status panels around the board to illustrate what they mean and how to use them.