## Posts tagged ‘Appel’

### Math Clocks

Jiminy. The folks at Clock Zone make a math class wall clock — and I would like to be the first to publicly chastise buy.com, amazon, and anyone else who is selling it. It contains at least two mathematical errors:

SPOILER ALERT: In my rant below, I identify the errors in the clock. If you’d like to identify them for yourself, don’t read any further.

I say “at least” two errors because there may be more. The obvious errors are for 9 (the expression assumes that the exact value of π is equal to the common approximation 3.14) and for 7 (because the equation is quadratic, *x* = 7 is only one of the answers; the other possible answer is *x* = ‑6).

More generally, I have an issue with any of the algebraic equations that are meant to represent integers. For instance, the equation 50/2 = 100/*x* has solution *x* = 4, but I believe that it is incorrect to say that the equation itself is equal to 4. So perhaps the clock has four errors, if you consider the algebraic equations for 4 and 10 to be erroneous, as I do.

This clock is meant to be a math joke. Edward de Bono in *The Mechanism of the Mind* (1969) suggested that when a familiar connection (such as seeing the numerals 1‑12 on a clock) is disrupted, laughter occurs as a new connection (seeing mathematical expressions instead of numerals) is made. Sadly, math jokes are supposed to make you laugh… yet this clock makes me want to cry.

To ease the pain, I did a little research and uncovered several clocks of famous mathematicians. I present them here for your enjoyment.

Leonardo da Pisa:

Kenneth Appel:

Rene Descartes:

Karl Friedrich Gauss:

### Make Your Own (Math) Joke

Here’s my favorite joke (even though it’s not a math joke):

Two cannibals are eating a clown. One turns to the other and says, “Does this taste funny to you?”

It’s beautiful in its simplicity. Just 19 words, none of them extraneous. It’s a triumph of humor, and I tip my hat to its creator.

I love this joke, and I would have included it in *Math Jokes 4 Mathy Folks*, but it’s not a math joke. But it got me to thinking — could it be altered so that it could be a math joke? That is, can you put two different words in the blanks below so the joke is more mathy? And can you do it so that it’s still reasonably funny?

Two cannibals are eating a ________. One turns to the other and says, “Does this taste ________ to you?”

I offered this challenge to attendees at the Math Joke Hour that I hosted yesterday at the 2010 NCTM Annual Meeting. They came up with quite a few that are worth sharing, though not all of them are mathematical:

math teacher… chalky

statistician… normal

Kenneth Appel… fruity*

actuary… bland

angel… heavenly

mechanic… greasy

Iowan… corny

pot smoker… mellow

Warren Buffett… rich

old seafarer… salty

bodybuilder… strong

Got another worth sharing? Leave it in the comments section.

* Kenneth Appel is the mathematician who, along with Wolfgang Haken, proved the Four Color Theorem in 1976.