We sure wish we’d had a teacher like [Danko Bertović]. He built this beautiful circuit sculpture to teach his students how to count in binary and convert it to decimal and hexadecimal. If you… ...

Technically, it isn’t a BCD (Binary Coded Decimal) watch. The minutes on this watch are displayed in pure binary, e.g., 32, 16, 8, 4, 2, 1, while if BCD, it would be 4, 2, 1 (tens digit), then 8 ...