## Sunday, March 14, 2010

### Happy ∏ Day!

click on the graphic to view it full size in a new window

It's been a rough day in New Hampshire. We lost power most of the day on Saturday because of this big Nor'easter that is going on to the south of us. And today's rain/sleet/ice/snow/wind storm has been wreaking havoc on the Internet connection. Weather like this chills your bones. So I'm making pot roast, watching movies and doing laundry to pass the time while I upload and post material.

I forgot about ∏ Day until this morning (as I also missed church because I never fixed the clocks last night). On this ∏ Day I am presenting an Excel graphing activity I use with older middle school students. All students seem to have a problem grasping the concept that ∏ is a non-repeating, non-terminating decimal. They have an even more difficult time understanding that all of the digits 0-9 occur with the same frequency. Before we do this activity, my students already have a lot of experience with counting occurrences of heads and tails and counting the outcomes of rolling a die. They also have learned how to record their results in a spreadsheet.

I then demonstrate how they can use an Excel spreadsheet to simulate the roll of a die or the toss of a coin and how to count the outcomes using the COUNT function and other formulas. They also learn how to import raw data of a comma- or space-delineated file into Excel.

With all of these new skills, my students are then able to use Excel to count the occurrences of each digit in the decimal portion of ∏, whether it is 1,000 digits or 1 million digits. I encourage them to import different amounts of data. Then they compute the probability of each digit occurring in ∏ and find that the more digits of ∏ that they use, the closer the probabilities of each digit appearing approach 10%. This result is similar to their coin toss experiments.

It took several hours, but I have uploaded the files to my static web pages at meeyauw's hideout. I even included a file that contains the first million digits of ∏. You can study the formulas used in the spreadsheets and see the graphs we created. The graphic above used 10,000 digits of ∏ to find that the probabilities of a digit appearing in the decimal portion of ∏ approach or are at 10%.

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Below is my playlist of ∏ Day videos from YouTube. I haven't seen most of them because of the Internet problems.

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My last Pi Day contribution today is the ever so much fun site, the Pi Search Page. When students have done their spreadsheets and charts, they are encouraged to play with this site. Hopefully this site reinforces the concepts that I want them to understand. Today I entered the Apple Computer Store telephone number (1-800-MY-APPLE or 1-800-692-7753). There was no result when I entered the entire phone number. But when I entered 6927753, the results were:

The string 6927753 occurs at position 24,791,273 counting from the first digit after the decimal point. The 3. is not counted.
The string and surrounding digits:
51437113655565872488 6927753 92233691772360083137
this query took 0.007674 seconds

HAPPY PI DAY!

moar funny pictures

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#### 1 comment:

1. We don't even know what Pi Day is....mom is putting her thinking cap on about it.
Hope you got your power back on for good.
Love the kitty pic.
--JB