I was an organic chemistry major and graduated with my BS in the late-60s long before electronic calculators. (We had honking-big Marchant mechanical calculators in a room somewhere in the building and they were almost always occupied at most convenient hours and the next best calculator was the slide rule.)
I had an organic quant prof who expected us to be able to hold our writing instrument in one hand and hold a slide rule in the other and do the math with his exams timed with that capability in mind without ever putting either down.. He even had sessions after his classes instructing in the proper use of the "slip-stick" and ways to achieve greater precision which he expected to be at least 2 significant digits approaching 3 which was about the width of the scribes on the rule. In fact, I believe he claimed there was some relationship between the precision of those scribes and the capability of the slide rule but I can't recall his rule. Of course, he advocated a circular slide rule as the better choice over a linear slip-stick as it was far more compact for the precision. I have a small Fullerton 1450, 85mm circular in my desk and a slightly larger one in my go-bag which I keep against the time when the revolution starts. I had a K&E about 2.5 inches wide, a wooden - not bamboo - slide rule that got stuck when humidity was high, a couple of Dietzgens, Pickets, etc. I wish I had any one of those to show my sons and their kids - they wouldn't believe how such arcane devices landed us where we are now.
Of course, the E6b is nothing but a special purpose circular slide rule which scares many student and novice pilots but I felt quite comfortable with it during pilot training and still keep one handy in the cockpit.
So ends my paean to the lowly but powerful mechanism of the "bad old days".
2sheds