When I went through high school, their use had been discontinued. I learned how to use one anyways. Then I got one of those fancy 4 - function calculators that fit in my pocket with the little lamps that had a collection of filament shapes inside that KNEW THE ANSWER and I never looked back. Then one day I found myself in a machine shop with a vernier caliper.
Deja vu all over again. ;-)
I think my poor boss soiled himself when I was able to read it on the first go-round.
Bill