This game will test your math skills and problem solving skills. There are rows and columns of squares. Each row requires a certain number in order to complete, but the column also has a number and it isn't always the same number. Each color has a different value assigned to it, so you have to click through to change the value of the row/column based on the colors in each. The game is difficult, but very addictive and it will keep you adding and thinking for hours.