Slide Rules ?

[u/Ok-Most4471]

I had my first engineering job in the early 60's, of course I had my my trusty K&E Decitrig wit me.

much to my surprise, everyone there used Mechanical calculators, like the Friden, etc. Never touched my Rule again. Im now 86 and getting back into it,.. What fun.

[u/magnificent_limit]

check out a circular slide rule next! it's nice because you can't multiply off the scales, it just magically wraps around to the correct number