I don't have domain expertise here, but I suspect one example would be simple numerical calculation: electronic devices are so widely available today that hardly anyone can do long division in their head, or by hand for that matter, whereas relatively many more people in 1970 probably could, and had no ready electronic alternative. Whether people in 2019 could learn this skill as well as people in 1970 if it were deemed a priority, I don't know, but I think it's fair to say that the skill was much more valued in 1970, and considered a more integral aspect of "intelligence." (And of course, numeracy only became so important relatively recently in history -- centuries ago, the ability to successfully hunt and forage was much more essential to most people's definition of "smart" than anything involving numbers.)
I’ve not seen any numerical calculation in an IQ test I’ve done that isn’t in some form just a puzzle and that doesn’t get more advanced than basic arithmetic. Being able to reason about numbers, addition, subtraction, multiplication etc. is perfectly in line with measuring intelligence.