The Calculator app is probably one of Apple's most-used iPhone apps, yet I always meet people who don't know all the little tricks there are to using it more efficiently. You may know most of them, but there's a chance you don't or at least forget about some of 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 for everyone, from a total smartphone newbie to somebody who's owned iPhones since iPhones were a thing, and even professional mathematicians. For the most part, I've... more