This set of foam dominoes can be used as simple flash cards for practicing and reinforcing key math concepts, or as a game for up to four players.  It includes two sets of 24 colour-coded dominoes (48 pieces in all), with one set focusing on expressions in algebra and the other on equations.  Each domino measures 8 cm x 4 cm (about 3" x 1 1/2"), and the set comes with instructions and activity suggestions.