HOW TO PLAY: Swipe (Up, Down, Left, Right) to change number on tiles to Zero. Drag square sum-tiles through sequence of round num-tiles so sum-tile at the and of track is equal to zero. Mathematics is fine. In combination with a mysterious riddle is in this game for a long time what to do. Try to solve simple and complex levels of math game Sum track. For anyone who likes math and logic games. Try it and you'll have fun.