On Thursday, in the spirit of Halloween, I presented the class with a set of vampire teeth and the Pandemic lesson from @Mathalicious: http://www.mathalicious.com/lesson/pandemic. If you haven’t checked it out, you definitely should, great stuff on their site! Also, this post will not make much sense unless you understand the premise of the lesson 🙂

Being a 5th grade class, I knew we wouldn’t get into the exponential representation, but I wanted the students to reason about what was happening each week and look for patterns in the problem. They did not disappoint.

The students were very quick to jump right in…monsters, blood, vampire teeth…they were all in! The majority of the class were fairly quick at recognizing the number of vampires was multiplying by two each week. I found the biggest struggle for them was to keep the total population in mind. For example, in Week 1 when there were 2 vampires, there had to be 138 humans because there always had to be a population of 140. The following week when there were 4 vampires, the students subtracted 4 from the Week 1 human population, arriving at 134 humans, but the total population would only be 138. It was hard for them to realize they only needed to subtract the “new vampires” from the human population, not the current vampire population. It was a struggle and some got frustrated when I would ask them if people left the town? Did you lose dots from your array? They wanted the answer, it drove them crazy and I loved it!

At the end of the lesson, I had two groups who had gotten through the world population piece (they were very surprised that it didn’t take them that long to get to 7 billion)! They predicted it was going to take them forever!

Before leaving, I had everyone reflect on which Math Practice(s) they felt they best reflected their work in math class that day and here are just a couple examples:

Math Practice 1 was by far the unanimous choice because they felt the struggle of working through a math problem. I loved reading their reflections, and it made me realize that I need to really work on asking that question more often and push them to look at the other Practices in their work.

-Kristin