The Rule of 72 has likely made its way to many table conversations about money. It’s a simple, almost magical calculation that tells you how long it takes to double your investment. And you don ...

Some handy math tricks can help you figure out each of these situations quickly — and without having to resort to pulling out the calculator on your phone. We've assembled eight such tricks below.

Stupid math tricks for smart investors from Jack Brennan Up 100% and down 50% puts you right back where you started, right? Wrong! The former Vanguard CEO has more common wisdom for all investors ...