Are your second graders working on two-digit subtraction this winter? This activity can be used for whole group or as a center to practice mental math strategies for subtraction. Differentiate by having your students begin with just subtracting ones on the one star game, and move up to subtracting tens and ones on the two star game. Answer keys are provided for both levels. This file includes two level game boards, two answer keys, two dice, and two recording sheets.