Forbes contributors publish independent expert analyses and insights. The tactics everyday people use to “FIRE” and pursue their dreams. If you want a tough challenge to address in your spare time, ...

Pilots frequently need strong mental math skills for various in-flight calculations when calculators or other aids are unavailable. "Mental Math for Pilots, Third Edition" by Ronald D. McElroy ...

You probably haven’t had to do longhand math in years, but you do mental math every day. Or maybe you google math problems ten times a day, because you’ve forgotten how to do any math beyond your ...