Sum-Up LED Watch

How quick can you read the time? The "Sum-up" LED watch is a modern and innovative watch challenges your maths! 4 LEDs indicate the binary numbers of hour (1,2, 4, 8). 6 LEDs at the bottom indicate the binary numbers (1, 2, 4, 8, 12, 16) of minute. Adding up the numbers to determine the time. It's really fun!