Sunday, July 14, 2013

Constructing Modern Math Knowledge

Ihor, April, and Jim celebrating April's Average Traveler Award
I spent this past week at Gary Stager's Constructing Modern Knowledge Conference in Manchester, NH. There was quite a turnout. Over 150 educators from all over the world enrolled. The modern knowledge that the folks worked on included some strange sounding tools like Raspberry Pi, Arduino, Scratch, conductive paint pens and plenty more. (See "Oh, The Stuff You Might Learn With at CMK 2013") I shied away from being that modern and decided on a more familiar project.

When I walk into a room full of people, I usually think of the famous birthday problem which predicts that if you have 23 people in a room there is slightly better than a 50% chance that at least 2 people will share a common birthdate (month and day only). If there are 100 people, the percentage jumps to more than 99% certainty that this will happen. With a 150 people attending I thought of a more interesting crowd sourcing activity that determines who the "average traveler" to this conference is. Basically I find out which person traveled the shortest distance from the mean distance of all the travelers. I used Google Docs forms and spreadsheet to get the data and Google Maps to display it. (The original plan was to write a Scratch program to do it and this is currently a work in progress.) The form asked each conference participant to enter their name, home or school address and distance traveled (in miles). The results appeared in the Google Docs spreadsheet. See Table 1.
Table 1 - Top 20 finishers
As you can see from the table, April Gustafson was our average traveler. In addition to entering their mileage, participants also added a marker on a Google Maps page. I made a snapshot of the markers and used Geometer's Sketchpad to draw the circle with a diameter approximately equal to the mean of all the travelers. You can see that April's balloon was closer to the circle than any of the other travelers!

I want to thank Jim Scribner for his assistance and friendship doing this project. We discovered a mutual love of baseball that goes way back. Do you remember the Pirates lineup in the 1979 world series? We did with just a little help from Google.


  1. Well, there was a guy named Willie Stargell...

  2. The original activity page that I handed out at the conference is now on the web at

    Thanks for your participation.