That's a great post. Find a Marchant 20 register calculator next.
And you will have the state-of-the-art for some of us when taking trig and physics in HS.
Similar to some of these, not identical.
I worked in a physics lab at the local State University while in HS, friends would come over and we'd pound on those things forever. Had to either estimate square roots or use logs in those days.
Slide rules and Marchants. They don't do it like they used to, and a damned good thing it is!
Great post.
Arf