The Calculator app is probably one of Apple's most-used apps on the iPhone, yet I meet people all of the time that don't know all of the little tricks there are to using it more efficiently. You may know most of them, but there's a chance you don't know every single one or simply forgot about them. What a "hidden trick" is to some people might be obvious to others, so feel free to skip right by the ones you already know in the below list. This roundup is meant for everyone, from a total smartphone newbie to somebody who's owned iPhones since iPhones were a thing, and even professional... more