Numberphile put out a great video on the so-called “pancake number” – see the 3rd video below. I watched it when it came out and thought it would be a fun project for the kids to explore.

Unfortunately I got mixed up on the procedure when we were doing the first two parts of the project this morning. So, at the beginning of the project we weren’t actually studying the “pancake numbers” but rather a variant. Not a big deal, though it required an explanation after we watched the video!

We started with an introduction to the sorting problem and studying the case of trying to put 5 elements in order using (what I thought were) the pancake sorting rules.

Next I asked the kids to explore the problem in general and they looked carefully at a few simple cases. One neat thing here is that one relationship between sorting N and N+1 blocks that they thought would be true turned out not to be true.

Now we move on to view the Numberphile video. Katie Steckles does such a great job here (and I love that the sheet of paper from the Graham’s number video is up on the wall behind her!).

To wrap up we returned to the white board and played around with the correct rules. It was nice that they were able to find an example with 3 blocks that had a different result when we applied the right rules.

Definitely a great video by Numberphile and a fun project for kids. It is always really fun to play with an unsolved problem that is accessible to kids.