How Old Are You?

We were writing equations for conic sections (okay, fine, my students were working in groups and I was coloring) when one student whispered something to her neighbor. He responded “you want me to just straight up ask?” and she nodded, wide eyed. He turned to me, noticed I was already listening and explained “Well, we’ve had this ongoing discussion all year about how old you are. It comes up every few classes. In fact, one day we wrote down some ranges.” They start flipping through their notebooks eager to share the analysis they started. I like where this is going and wait to see if it’ll play out the way I hope it will. Right on cue, another group asks what we are talking about and with very little prompting I get a student at the board soliciting a minimum and maximum age prediction from every student in the class. Some are wide: 19-47 while others are narrow 27-30. I am thrilled because I remember someone blogging about this exact activity (comment if you have the link please!) and his students were amazingly accurate. My experiment worked out just as well. The mean was 28.3 and the median was 28. I turned 28 in February! Of course I let the suspense last just a bit longer and instead of telling them my age, defined perfect numbers and informed them I am a perfect number. So today my students learned my age, about perfect numbers and that as a group they are awesome at analysis. One student proclaimed that they should go out together and offer to predict things for the world. Another wants to repeat this process every time a new adult walks into the room (after declaring this would be far less exciting for students). I hope he remembers next time someone shows up to observe the class!