Q: What's purple and commutes?
A: An abelian grape.
Q: Why did the mathematician name his dog "Cauchy"?
A: Because he left a residue at every pole.
Q: Why is it that the more accuracy you demand from an interpolation
function, the more expensive it becomes to compute?
A: That's the Law of Spline Demand.
Q: How many mathematicians does it take to screw in a lightbulb?
A: One, who gives it to six Californians, thereby reducing it to an
earlier riddle.
-- from a button I bought at Nancy Lebowitz's table at Boskone
Q: What do a mathematician and a physicist [or engineer, or musician,
or whatever the profession of the person addressed] have in common?
A: They are both stupid, with the exception of the mathematician.
Q: What do you call a teapot of boiling water on top of mount everest?
A: A high-pot-in-use
Q: What do you call a broken record?
A: A Decca-gone
Q: What do you get when you cross 50 female pigs and 50 male deer?
A: One hundred sows-and-bucks
Q: Why did the chicken cross the Moebius strip?
A: To get to the other ... er, um ...
Q: What is the world's longest song?
A: "Aleph-nought Bottles of Beer on the Wall."
Q: What does a mathematician do when he's constipated?
A: He works it out with a pencil.
Q: What's yellow and equivalent to the Axiom of Choice.
A: Zorn's Lemon.
Q: What do you get if you cross an elephant with a zebra.
A: Elephant zebra sin theta.
Q: What do you get if you cross an elephant with a mountain climber.
A: You can't do that. A mountain climber is a scalar.
Q: What do you get when you cross an elephant with a banana?
A: Elephant banana sine theta in a direction mutually perpendicular to
the two as determined by the right hand rule.
Q: To what question is the answer "9W."
A: "Dr. Wiener, do you spell your name with a V?"