All of this deduction you just did requires prior knowledge of the existence of logic tests and that written tests work like that, which is purely modern cultural knowledge. No one is born knowing that a “written test” is a thing. There was a time period in history where this was NOT obvious, even though it is obvious to anyone now.

In 1904 people had never seen a math problem?

You assume the illiterate or under-educated classes to have seen a math problem? Or have the incentive to play this pointless "game" called an IQ test? (unless they're paid a dollar for every "correct" answer they give)

Are you making a claim about the past or today? If the former, public education had been established for close to a century already, so yes, I do have the expectation that levels of exposure would not be that much worse than today. If the latter then it doesn’t exactly explain why people have gotten better at it over time.

> I do have the expectation that levels of exposure would not be that much worse than today

I would expect that in 2023 everyone would know how to search for "literacy rate in 1900" in Google (or Bing if you will) instead of asserting your flawed expectations and wasting everyone's time.