I think that would depend on the knowledge the subject had before entering the testing scenario

That was my main point on this test being an interesting question starter, but not being conclusive enough because we don’t know. The subjects were purposefully random and not evaluated before the test.

fractions because it’s something that everyone who’s gone through the public education system should know

Yes, well. I don’t think I need to comment on how bad the US system has become. I wonder how much higher the assisted people did while they had the help compared to others?