Here is a cool math clock that gives your brain a workout and improves your calculation speed. The Albert Clock digitally displays simple math equations. It has 6 levels of difficulty and supports 12 and 24-hour time formats. You can easily modify the speed of equation change per minute.
More gadgets like this: here
**Disclaimer: Our posts may feature aff links. As an Amazon Associate, we earn from qualifying purchases. Please read our disclaimer on how we fund this site.