When you click on the Start button, the 16 figures will be randomly rearranged and you have 16 seconds to memorize their positions. Then, the figures will be replaced by random numbers. Now take as much time as you need to enter the numbers corresponding to each figure in the text fields under the Start button. You gain 1 point for each correct number, and lose 1 point for each wrong number. When ready, click the relevant button near the bottom of the page to find out your score.