Dad's Addiator Calculator

[@mandolinic]

I had one of these at school in the 1960s. It's dirt cheap, very simple, and very fast to use. The stylus is far more convenient (and a lot faster) for entering values than most other adding machines of the era. Use this to tot up a column of numbers and it will do it almost as quickly as a modern calculator. Of course, the down side was that multiplication and division are very difficult, which is why we also had slide rules!

[@LunarDelta]

My dad had an Addiator Duplex from Addiator Gesellschaft and it was really cool and super sturdy too.