Also, when I first started things were relatively straightforward. I didnt have to deal with 1/2 or 1/3 stops. The markings on the lens and body were always in 1-stop increments. For "normal" photography, I just ignore the reciprocal numbers ie f/16 1/125s etc. I'd just remember that it's 16 and 125. If I decrease one of the numbers, I'd just increase the other eg 8 and 250 would give the same exposure at 16 and 125. Of course, like I said we didnt have 1/2 or 1/3 markings then so it was relatively simpler.