Sum12 is an addictive domino game, which trains the mental arithmetic. It is equally suitable for infants and adults. The goal of the game is to get rid of all domino tiles to clear the playing area.The game starts with domino tiles, whose pips are visible as well as with upturned domino tiles. You have to find tile couples, whose value of the pips results the sum of 12.If the pips are calculating the sum of 12, they will be removed from the playing area. The freed up stones can be turned around afterwards. Not every game comes inevitably to complete the clearing of the playing area.