I recently discovered the website TV Tropes has two math-related sections:
24; the first season takes place “two years to the day” after Jack Bauer lead a covert strike in Yugoslavia during the 1999 Kosovo War. It is also a presidential election year. Later seasons seem to have decided that season 1 was set during the 2004 election, meaning either that Jack is bad at math, or that he lead a covert strike against a key figure in the Milosevic regime two years after the collapse of said regime.
Enterprise in describing the Expanse, the mysterious spacy-cloudy-thingie that the Xindi are hiding in. It’s said, on screen, that it spans 2000 light years, and is 60 light years from Earth. Simple trigonometry shows this thing, seen from Earth, would therefore occupy 179.9 degrees of the night sky (out of 180) at least part of the year. Apparently, we just didn’t – you know – notice that HALF THE FREAKING SKY was missing a lot of stars.
I also recommend the extensive section called You Fail Biology Forever.
Additionally check out the description of Eigen Plots and the link to the webcomic describing eigenvectors in the context of comic book plots.