You know, in my day, we used a physical calculator to add, not a calculator app on a computer. Okay, so maybe the advances in basic math tabulation have slowed down a bit, but that wasn't the case in the age of the slide rule calculator. Today from the good folks at RetroCalculators.com (who knew!?) we're taking a look at an interesting slide rule / and addiator. (Addiator may be my new favorite word, even if spell check doesn't recognize it as word) I've always been fascinated by the world of mechanical computation, even if I'm often left stupefied by just how it works. This handy little unit stays just on this side of comprehensible. And I'd highly suggest checking out the other cool retro calculators on their site.