Look up a now mostly outdated device called a slide rule. This was how they did mathematics before calculators and computers. This is basically a compressed version of what would have been in the back of most math books, that is large tables of values for sine, cosine, logarithms in base 10 and e (natural logs), square roots, possibly cube roots, etc... Needless to say everything was much slower and took a lot more arithmetic. What our calculators do today is absolutely no different that what these slide rules do, it's just that their tables are much larger and they do the calculations for us. As for the detail into which they went, it was no different. They learned the exact same stuff that we do today, it's just that they probably didn't do quite as many problems because of the arithmetic amount of arithmetic involved. Not speaking from person experience, just what I've heard my mom talk about and the horror stories of my professors.