Bedazzled

Some trivia about the Faustian film "Bedazzled" (which came out in the year 2000 and stars Elizabeth Hurley and Brendan Frazier) regarding Fermat's Theorem (from moviemistakes.com):

"This is not a mistake but something clever.
When the Devil was a schoolteacher, the first equation on the board was Fermat's Last Theorem
(X n + Y n = Z n   for n > 2).
It was proven in 1993 that there is no integer solution to this equation; exactly the kind of problem the Devil would give to an algebra class, but not really expected in your standard Hollywood film."

Annapolis

In the movie Annapolis, plebes doing a navigation calculation report an answer "40 degrees, 80 minutes."   Well then, that makes me 5 feet 14 inches tall and my age is 39 years 251 months!

Buck Privates and In the Navy (Abbott and Costello)

Abbott and Costello made arithmetic shenanigans the basis of a number of their comic dialogs.
Click here for examples of their dialogs.