Apparently the writers of The Simpsons would occasionally put examples of maths humour in programmes. The following is one example1.
1. For the less mathematically inclined, this reads “I ate some pie”. The only non-obvious element might be the square root of -1, which is conventionally denoted in maths by the symbol i. And the Greek letter sigma is used to denote sum. It’s really more mathematical than humorous.↩