On March 14, which by coincidence is Eistein's birthday, Mathematicians all over the world celebrate Pi Day, at 1:59. The choice of the day and time is easily understandable, if we think or the first digits in Pi: 3,14159.

Since it was such an importand day for mathematicians of all ages all over the world, we decided to celebrate it together by a collaborative activity. Here are some of the activities that we planned, did and then discussed:

• express all he numbers (out height, weight, age, even the time) that day in radians,
• experimentally determine the value of PI
• play games connected to the topic
• hold our hands to make a circle or form a human Pi shape
• create a "Pi ambiance"-use a Pi wallpaper, listen to Pi music, such as the one in the video, 

• make Pi things- mugs, T-shirts, posters
• have a contest about memorizing the digits of Pi,

Here is a Geogebra illustration of Archimede's method for calculating Pi. It was so nice to think that it was a shared activity, and that we will be able to compare what we did!

The result is this video we created together: