Archive for November 19, 2010

Investigating National Pi Day

American Express is running ads for Small Business Saturday (November 27). It’s a good idea, but I was taken aback by one of their radio spots, which says:

There’s a day for everything — Thesaurus Day, Groundhog Day, National Pi Day…

That last one caught my ear. I’ve celebrated Pi Day for years, but National Pi Day? At first, I was sure the copywriters for American Express had screwed the pooch on this one. Pi Day cannot be a national holiday, because π is a universal constant. And the United States is not the only country that writes dates in the mm/dd format — so do Canada, Greece, Kenya, China, and the Phillipines, among others.

I did a little investigating. Sure enough, there is a National Pi Day. On March 12, 2009, the U.S. House of Representatives passed HRES 224, a non‑binding resolution that declares:

Whereas Pi can be approximated as 3.14, and thus March 14, 2009, is an appropriate day for “National Pi Day…”

The resolution continues:

The House of Representatives supports the designation of a “Pi Day” and its celebration around the world.

Doesn’t it seem a bit incongruous to declare a National Pi Day but then support its celebration around the world?

At least HRES 224 correctly states that π can be approximated as 3.14. This is in stark contrast to House Bill 246, passed by the Indiana State Legislature in 1897, which stated, among other things:

that the ratio of the diameter and circumference is as five-fourths to four

thereby implying that π = 16/5 = 3.2.

What a difference 113 years make, huh?

A geometry teacher hands a cylindrical metal container to a student and asks her to find the ratio of the circumference to the diameter. She thinks for a moment, then offers, “Um… pot pi?”

November 19, 2010 at 3:57 pm 2 comments

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The Math Jokes 4 Mathy Folks blog is an online extension to the book Math Jokes 4 Mathy Folks. The blog contains jokes submitted by readers, new jokes discovered by the author, details about speaking appearances and workshops, and other random bits of information that might be interesting to the strange folks who like math jokes.

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November 2010

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