A key plot point is the idea that the Antikythera mechanism was actually made by Archimedes as a way to predict spacetime distortions that allow for time travel. (In reality, there is no clear evidence linking Archimedes to the device and, of course, there is no reason to think it had anything to do with time travel.) So, characters frequently mention Archimedes, who is described as a mathematician and a genius.

Indy and his colleagues are surprised that the device seems to work. (The real device certainly was no longer functional after over 2000 years under the ocean!) When one of them says so, a Nazi scientist bursts in with armed thugs and says "Of course it works. Math works!"

Indeed, it works well enough to take them back in time where Indy gets to meet Archimedes (whom he recognizes immediately somehow).

A portrayal of a historical mathematician, several modern characters talking about him as a genius, and the bit of pro-math propaganda in the line "Math works!" (though said by a Nazi) comprise the entire math content of this film. Not a lot, but as I said, just enough to convince me that it should be included in this list.