Miss Tsypenyuk's Blog: "The Locker Problem"

I have a confession. I used an *old* math problem. One that parents told their children they remember seeing in school. One student told me her step-father said, "They're still doing this problem in school?!?" Yes, I used an old problem. BUT it was awesome! It's the age old "locker problem". There are 100 lockers. 1st student opens all the lockers. 2nd student changes the status of lockers with numbers that are multiples of 2. 3rd student changes the status of lockers with multiples of 3. And so on.... Which lockers are left open?

I don't remember much about this problem from when I was in school. But two years ago, I went to a math workshop and learned about the math behind this problem. What it actually reveals. I thought it was interesting, but still didn't see a place for it in my classroom. But then I realized, students need a chance to come up with strategies to challenges. Determine their own materials and embrace the struggle. So this year I piloted "The Locker Problem". It was so fun to watch! I saw all sorts of different strategies. Some students drew out the picture on whiteboards. Some recreated it with post it notes. Some went out and labelled actual lockers. One student had an idea of re-enacting it with books. Some realized their strategy was too cumbersome and switched methods. We all eventually got to the answer. Hopefully tomorrow's lesson will reveal "why" it was the pattern they found ;)

The dry erase board method: