12 Math Knock-Knock Jokes

In a very old Second City skit, a man on hold complained (to no one in particular) about the hold music. After his complaint, a voice on the other end of the line said, “I’m sorry. Don’t you like my singing?”

“Who are you?” he asked, surprised.

“I’m your hold operator. If you don’t like music, I’d be happy to entertain you in some other way. Would you like to hear a joke?” she asked.

“Um… sure, why not?”

“It’s a knock-knock joke,” she said. “Are you familiar with the format?”

Now, that’s just funny!

My favorite joke to tell in the classroom is a knock‑knock joke, so I hope that you are familiar with the format.

Knock, knock.
Who’s there?
Interrupting cow.
Interrup — ?
Moo!

My sons are now of an age where they can understand jokes, and those of the knock‑knock variety are told daily in our house. (The knock-knock jokes at GRiN are a source of endless amusement.) Sadly, I didn’t know any knock‑knock jokes that are mathy… so I made some up. Here they are, 12 totally original (sort of) but not terribly funny math knock-knock jokes. Aren’t you glad you stopped by today?

Knock, knock.
Who’s there?
Lemma.
Lemma who?
Lemma in, it’s raining!

Knock, knock.
Who’s there?
Mode.
Mode who?
Mode the lawn. What should I do next?

Knock, knock.
Who’s there?
Slope.
Slope who?
Slope ups should stay on the porch.

Knock, knock.
Who’s there?
Convex.
Convex who?
Convex go to prison!

Knock, knock.
Who’s there?
Prism.
Prism who?
Prism is where convex go!
(Weren’t you paying attention to the previous joke?)

Knock, knock.
Who’s there?
Origin.
Origin who?
Vodka martini origin fizz?

Knock, knock.
Who’s there?
Zeroes.
Zeroes who?
Zeroes as fast as she can, but the boat doesn’t move.

Knock, knock.
Who’s there?
Unit.
Unit who?
Unit socks; I knit sweaters.

Knock, knock.
Who’s there?
Outlier.
Outlier who?
Outlier! We only let honest people in this house!

Knock, knock.
Who’s there?
Möbius.
Möbius who?
Möbius a big whale!

Knock, knock.
Who’s there?
Tangents.
Tangents who?
Tangents spend a lot of time at the beach.

Knock, knock.
Who’s there?
Axis.
Axis who?
Axis for chopping, saw is for cutting.