It all adds up with Plus Sign Mah Jongg! Take it back to grade school and play this Addition style Mah Jongg board game, or show your kids how fun adding can be with Plus Sign Mah Jongg! Match open mah jongg tiles to open up tiles below or beside them. Once all matches have been made, you are the mah jongg champion. Flower and Season tiles can be matched with any other in their tile set. Thus, a summer season mahjongg tile can be matched with winter season mahjongg tile. Wow!