I still have my Dietzgen Maniphase Multiplex decitrig log log slide rule. Freshman engineering students took an Introduction to Engineering  course which included instruction, practice and tests on using a slide rule. Many of us (dorks) carried the rule on a belt clip.
I will admit, tho, I much prefer my $15.00 TI solor calculator.
"There is nothing so frightening as ignorance in action."   
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"There is nothing so frightening as ignorance in action."