The plan for the Grade 4-5 night was the most difficult because there were so many things to narrow down! My goodness – how do you choose?

What I’ve settled on for now is the same sort of idea as in the two prior nights – 2 main projects with a 3rd in my back pocket if we have time.

The first project will be looking at the Collatz conjecture. I’m interested to try out this idea because:

(i) it gives them a view into an unsolved problem,
(ii) the problem requires only a little arithmetic, and should be accessible to 4th and 5th graders, and
(iii) John Conway’s extension gives them a fun opportunity for follow up if any of the kids are interested.

Here’s one of the talks we’ve done on the Collatz conjecture:

The second topic for the night will be the Monty Hall problem. This is always a fun problem to talk about in a crowd (and really only in a crowd!) because you get to tally up lots of results. Also, if you have a large number of people playing a small number of trials of the game, the results aren’t really obvious to anyone until all of the numbers are tallied. Oh, and if you want to get people arguing about math, there’s no better problem (though this is good and bad which is another reason why the large crowd helps!).

We’ve done a couple of projects based on this problem – here’s the most recent one:

Finally, the project that I’ll keep in my back pocket is the Chaos game. I’ll have to change this one if I don’t have a way to hook up my computer to a projector, but for now I’d like to give the kids a “wow” moment similar to what my kids had here (watch the whole 5 minutes for the set up, or just start at 2:20 for the punch line):

I’m super excited for these family math nights. Now that I’ve got the simple outline in my mind for the 5 nights it is time to start thinking about how to implement these projects with a large group.

This Collatz video is completely charming.