Thursday, March 14, 2013

A Pi Day Mystery

Click above to watch the simulation
My favorite Pi Day activity is the one where random needles dropped on parallel lines lead to an approximation of Pi. Why Pi? Good question. Pi is usually associated with circles. There don't appear to be any circles here. Right? Hmmm. Ponder that question while you watch the needles pile up and the estimate for Pi gets better. Well, at least in theory.

If you are more amibitious and would like to do it with your class see my lesson plan. Also, catch the video of the way one performer does the experiment with taped lines and baguettes.

Related links
Pi Day resources for March 14, 2014 or any day that feels right!


  1. This of course is the famous Buffon's Needle experiment. George Reese has a nice explanation of why it happens.


  2. Here is Wolfram's description