Combine in this game 3 (instead of 2) of the same tiles to remove those tiles. You can only select free tiles. Free tiles are highlighted. You can combine a flower tile with any other flower tile, the same applies to the season tiles.
Goal of Add It Up is to select numbers that add up to the target sum. You only have a limited amount of time to do so. The more numbers you select to get to the target sum, the higher your score will be. The faster you solve a sum, the higher your score will be.