Today I took error analysis to a new level with my students.
I stumbled upon this video over the weekend, with the hope of finding a clip to review and reinforce Friday’s lesson on similar figures. After watching the clip (which erroneously presents triangles that are not similar) I decided to use the video to promote student discussion – and boy did it! As students watched the errors unfold, they started looking around the room at one another and naturally began discussing the problem at length. Not only did I accomplish the desired review, but I saw students defend mathematics and become emotionally involved in the process!
The morals of this story:
1) Even a bad video can be used to create good mathematical communication.
2) Don’t believe everything you see on the internet. 😉