Introductory geometry proofs

Michael Pershan has been writing about kids and proofs lately. That writing has had me thinking a lot about how my kids approach proofs. Here’s one of Pershan’s posts:

Maybe it’s ok to prove obvious things

With the ideas about kids how kids learn proofs in my mind, I’ve decided to give a little bit extra focus on proofs while I review similar triangles with my older son. The problem we looked at last night was pretty challenging – and also pretty abstract. I was interested to see how he’d approach it:


The move from general to specific didn’t surprise me too much. If fact, I’m probably even encouraging this approach inadvertently with all of the math contest problems we look at. Rather than asking him to go back and work through the proof in general, I thought that I’d show him what the general approach would look like. Next week I’ll try to have him try some of the general proofs on his own.