Buffon’s Needle Experiment – 

Last year I was looking for an activity to celebrate Pi Day with my students, but I did not want to fall back on the old standby of measuring the circumference and diameter of different circles. After a little research online I found a great video by Numberphile.  Wow, I never imagined we could approximate pi by dropping and counting toothpicks!

Based on other resources I found online, I created a worksheet to lead students through the activity.

Buffon’s Needle Experiment Google Doc version

Buffon’s Needle Experiment pdf version

Here are the results from my Statistics class and also the results from when I did this with adults at a UCLA Professional Development.

Class Data - StatsClass Data - UCLA

Yep, I was pretty happy with the results!  You can also simulate the activity online and get even better results with more trials.

And they had lots of fun working on it as seen in pics below from when it was done at UCLA with math teachers.

We did a little bit of pondering to why this method approximates pi and what throwing toothpicks has to do with the number pi.  The video gives a little clue but other resources online go into much deeper detail if you’re interested.

Enjoy the activity and let me know if you try it out with your students!

A Very Cool Pi Day Activity that Does NOT Involve Measuring Circles

Comment or Question? Please add to the discussion!