Today is *pi* day, 3/14. You know, *pi*, the irrational number, 3.141592654… We all learned the basic formulas for a circle involving *pi* in school:

- (circumference equals
*pi*times diameter) - (area =
*pi*times the radius squared)

OK, no more formulas. I promise. With today’s computers, the value of *pi* has been calculated to millions of decimal places. However, not so long ago, the computations had to be made by hand, and it was a lot more difficult to determine the value of *pi*. The history of *pi* is one of progressive refinement:

- The Babylonians initially calculated
*pi*to the not-very-precise value of 3. - The Egyptians used a value of 22/7.
- And in the 5th century, the Chinese mathematician , Zu Chongzhi, determined
*pi*to be 355/113. This last value was within 8.5**millionths**of a percent of the now-known value of*pi*! Not bad for a guy with pencil and paper.

There are many websites devoted to *pi*, so I will not repeat all their information here. To get started with your *pi* learning, I would suggest www.exploratorium.edu. For even more information about *pi*, you can go to www.pi314.net.

*Pi* is not reserved for only the mathematicians. *Pi* has also been explored by musicians. Here is a fun, creative musical *pi* video:

So, how are you planning to celebrate *pi* day? Let me know. And me? What am I planning for my *pi* day celebration? I think I will have a piece of *pie*.

After you have your pie you will celebrate by flying home to Delta, right? I thought this was the day. It is so beautiful here I will celebrate by working outside all day.

I had never heard of national pi day but now Van and Bonnie are talking about it on WHO. I don’t have time to make a pie – too nice outside.