I’ve been sharing Jim Propp’s most recent essay (as of Sept. 2017) with the boys this week. The essay and our first two projects are here:

His essay is here:

Jim Propp’s How do you write one hundred in base 3/2?

Sharing Jim Propp’s base 3/2 essay with kids – Part 1

Sharing Jim Propp’s base 3/2 essay with kids – Part 2

Today I had the kids read the post. Here are some of the ideas that they thought were interesting:

With the camera off I started talking about some of the ideas from math that I knew that weren’t “useful” originally but became useful later. So, I turned the camera on and talked about it live. I would not be surprised if several of the things I said in this part are not historically accurate – this wasn’t prepared and was off the top of my head.

Next I asked each of the boys to design their own Engel machine. My older son went first and we counted to 10 using his machine.

My younger son went next. He had a different design and we used it to count to 10, too:

I’ve really enjoyed sharing Propp’s essay with the boys. It is a great way for kids to explore different bases and also a great introduction to some fun advanced ideas from math. I also love that kids can play with the “machines” using blocks – that seems to really keep them engaged.