International Pi Day

July 22nd is Pi Day (π Day), not March 14th.

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22 July ≈ 22/7 ≈  π

How do I to celebrate?

• make (and eat) a pie (Pi). Yes, pizza is a pie.
• recite all the digits of π that you’re memorized to the “amazement” of your “friends.”
• calculate pi in some unique way
• get together with some nerdy friends and nerd out in some other way
• hone your estimation skills
• do your homework

Wait, isn’t March 14th π day?

March 14th was declared π Day by U.S.-centric San Francisco hippies very recently. This follows on in the tradition of the Indiana Pi Bill, when some misguided lawmakers thought they could legislate the value of π. Archimedes and the Egyptians talked about 22/7 thousands of years ago, and it’s stood the test of time. Let’s celebrate!

Wait, isn’t July 22 “Pi Approximation Day”

Every written value of π is an approximation. Remove redundant words.

Doesn’t everybody in the world automatically think of “π” when they hear March 14th?

To most of the world, March 14th would be written as 14.03.2022, or just 14/3. Neither of these seems to have much to do with π.

In the U.S., the day and month are written backwards, so there is it written 3/14. But if you’re a human being, you’ve likely never seen “/” used to respresent a decimal. Americans generally don’t use periods to separate the day and the month. Honestly, Americans almost always write 3/14, which is 0.214285714… last I checked. What a mess.

How to write March 14	Who does this?
3/14	U.S. residents
14/3	Everyone in the world (except U.S.)
14.03	Global artsy-fartsy types
3.14	Pretty much NOBODY except StarTrek characters

Isn’t 3.14 really close?

Not as close as 22/7.

Approximation	Error	Error %
3.14	0.00159265358979…	0.05069573829%
22/7	0.00126448926735…	0.04024994348%

Isn’t 3.14 easier to deal with than 22/7?

Nope. 3.14 suffers the same problems as the metric system. Unless your circle has a diameter of 10 (or something similar), you’re got some 3-digit multiplication or division in your future.

With the nice fraction 22/7, you can often “cancel out” and get to your answer faster.