Binary Watch

it has two rows of LEDs to show you the hours and the minutes. You would ask me how it works. The upper row that indicates the hours has four LEDs. There are also four numbers above the LEDs: 8, 4, 2, 1. In order to find out how many hours it is now you just need to add up the numbers above the lighted LEDs. For example if the firs and the last LEDs are on it is the 8 and 1 then you just add it up and get the 9. It means that it is nine o'clock now. The lower row works just the same but it has more LEDs in it because it needs to display bigger numbers. There are six LEDs with six numbers below them: 32, 16, 8, 4, 2, 1.