Math Professor: Pick a number bigger than 7.

Student: 43.

Math Professor: That’s too big. Pick another number.

Student: 27?

Math Professor: Oooh! I like 27!

Math Professor: Pick a number bigger than 7.

Student: 43.

Math Professor: That’s too big. Pick another number.

Student: 27?

Math Professor: Oooh! I like 27!

Multivariable calculus professor: Does anybody have any questions about divergence?

Student: What does it mean?

Professor: Now, now. Let’s talk about curl.