# Video: The Aperiodical’s π approximation challenge

As part of our massive π day celebrations, The Aperiodical has challenged me with the task of assembling a group of mathematicians, some bits of cardboard and string, and a video camera, and attempting to determine the exact value of π, for your entertainment.

The challenge, which was to be completed without a calculator, involved using known mathematical formulae for π and its occurrence in the equations of certain physical systems. In the video below, seven different methods are used – some more effective than others…

If you reckon you too can ineptly compute a value in the region of π (in particular, if you can get a more accurate approximation than the date of π day itself, which gives 3.1415), feel free to join in the challenge and see how close you get.

## About the author

• #### Katie Steckles

Publicly engaging mathematician, Manchester MathsJam organiser, hairdo.

### 7 Responses to “Video: The Aperiodical’s π approximation challenge”

1. Steve Bell

Spot the (deliberate?) mistake. The probability of Buffon’s needle crossing the line is 2/pi, not pi/2. Pi/2 > 1, so that can’t be right :) Was Sam really working with pi/2 initially, or was this just a mistake in the presentation?

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2. Phil

For a mathematician you are not very good !
Pi = 3.141592 or 3.1416 after correcting to 4 decimal places.

You are one year too early !!!!!!!!!!

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• Christian Perfect

For an internet commenter you are quite annoying!

Among many other reasons this year’s a good reason to have ultimate π day, next year won’t have a really accurate π moment at 9:26:53, like this year did.

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3. Joshua

Of all the $\pi$ day activities posted, this is the best I have seen:

• shows a variety of places where pi shows up
• activities that are accessible to an incredibly wide range of ages and levels of mathematical sophistication
• great food for further thought on why the estimates are off, what to do to improve them, and alternative approaches (and many others, I’m sure)

Interesting that the average of the results isn’t a better approximation, even restricting to the ones involving physical measurements.

Also, might be worth noting that you don’t seem to have used the cheat for the Buffon’s Needle method (just aim for 355/113).

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