# Another Snow Day + Shapes

Two weeks ago I posted this image showing the impending snowstorm:

Then we had three days off of school while the city cleaned up the snow. Now we’re dealing with another storm, and today was day one of (at least) two snow days for this:

I’ve been a little bored, and trying to make up for it with a ton of reading. Today, I spent some time with Christopher Danielson’s new book about shapes — a simple book full of images like this:

with the simple question — which shape doesn’t belong in this set?

I was lucky to be in Danielson’s Hierarchy of Hexagons session at NCTM last April, and to spend some time with him at Twitter Math Camp last summer. I’m so so incredibly excited he is sharing his expertise in this format. His site about talking math with your kids is here, and the shapes book is described here and available as a pdf here. On top of that, he is giving the book a test-drive with elementary school classes, and talking about it, for instance here.

I think my students would really benefit from some of this type of reasoning. They struggled with this lesson on hexagons, but I think deeper than that is a need for more skill with logical reasoning and argument — and that is at the heart of what this book does. This type of question has a ton of applications — let’s do it with numbers, with graphs, with quadratics, and more. I think it would be a great task to review factoring strategies — which of these factoring problems is not like the other?

Anyway, if we ever get back to school I will be printing out a copy of this guy in color to keep at my desk, and start brainstorming about how to incorporate these ideas into my class.

Well done, professor. And thank you!