I was in high school when hand-held scientific calculators were just getting cheap enough that most people could afford them. They were still teaching the old ways of doing things. Slide rules have already been discussed here, but there were also books containing tables of trig functions and logarithms. We were taught how to look up things like sin(67°), and how to interpolate if the value we were looking up fell between two entries in one of the tables. By the time I got to college, no one was using slide rules or books of math tables any more, at least not in class.