Know of a math nerd? or a any sort of nerd in general? It may not make sense to you but this clock is a unique gift idea that any nerd could appreciate. Myself, I can't even figure out any of these numbers, but to be honest, I would probably first need to learn to tell time. The mathematics wall clock is a clock where each hour has a different math problem representing the number. The clock is made of matte black powder coated metal, runs on 1 AA battery, and measures 11.5" in diameter.