Joke: Do you believe in one God?
Mathematician: Yes, up to isomorphism!

Joke: A billion neutrinos walk into a bar. A couple say ouch.

Joke: Why did the cyclops have to close his school?

Joke: Do you wanna hear a construction joke?

Joke: An onion field is a commutative onion ring in which every nonzero onion has an inverse.

Joke: Chuck Norris is a firm believer in warming up before you workout. He always does an Ironman before working out.