## Saturday, April 9, 2016

### Can You Solve the Locker Riddle? A Ted-Ed Lesson and How to Write One

Two of my favorite problems have become Ted-Ed riddle videos. I wrote about the Ted-Ed Lesson "Einstein's Riddle" here. I worked with the creator, Dan Van der Vieren, the week before his lesson came out when he taught my class how to solve the Rubik's Cube. I was so impressed with his riddle that I asked him how he was able to create it. He told me about the nomination form, and I filled it out and wrote about the problem that I do every year in my classes, The Locker Problem.

The idea, of course, is not to write out all 1000 lockers, but to create a smaller, similar problem and look for a pattern. I use this to teach my students about tenacity, collaboration, and the value of using the solution to a small problem to solve a bigger one.

Within a few weeks, I heard back and was scheduled for a 30-minute interview with someone from Ted-Ed, and we talked about how to change the problem to have a story line, and having something in the lockers that remain open. I brought it up to my Problem-Solving class, and we ended up making a riddle that would involve having to solve a problem to earn an inheritance. Once that was done, I sat one night and wrote the riddle, very excited that the number of words in the sentence that I wanted in the lockers was ten, and that there were exactly ten lockers open. Often when I give this problem, I ask, "Which lockers are touched exactly twice?" So I threw that piece in their as well. As an author of a Ted-Ed riddle, you also need to come up with 5 multiple-choice questions, 3 open-ended questions, additional resources to explore, and a guided discussion question.

The people at Ted-Ed are awesome! They are extremely professional and always got back to me within 24 hours, offering advice and helping me with any questions I had. And the animation is THE BEST!! Who cannot love that little girl??

Within a few months, it was up! The idea is that teachers can even customize a lesson of their own with the riddle. Here is the actual link to the entire Ted-Ed page that contains the riddle: http://ed.ted.com/lessons/can-you-solve-the-locker-riddle-lisa-winer.

My students LOVE these riddles, the first five of which can be found here. They beg for more. Do you have a good riddle? Consider nominating yourself and writing one for Ted-Ed.