Gray numeric tiles on the playing field want to get a bright color, but for this they need to be connected in logical chains. The conditions are simple: at the top there is a task - the amounts that need to be made up of tiles. Each square has a branch, through which the connection will occur. Given the numbers, combine the tiles, if you get the right amount, they will be colored. Elements on the field in Chain Sums can be moved by clicking on the desired place or swapped. Think, think and solve the puzzle until you achieve the desired result. The game has fifty most interesting levels.