It's been a while since I last wrote up a specific lesson idea so when my friend Garth asked about recursion ideas I thought I'd write this one up. This is a unit I used to teach in my intro class at Stuy using Racket (nee Scheme) but I coded up a quick and dirty Python version. Recursion is a polarizing topic. Some people love it, others hate it. I'm sure the usual suspects of intro recursion problems doesn't help.

When I wrote about the HighWebEd I mentioned John William''s talk on Agile. He spoke about how the movie Airplane! was filmed in an Agile manner and gave as an example the development of the "jive" scenes. <iframe width="560" height="315" src="https://www.youtube.com/embed/zdCjbJ6NEfc" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe> Apparently the creative team had a script but it wasn't working. The first pair that read for the role, Norman Gibbs and Al White had their owned take.

If you check out Twitter, Facebook, Medium and other blog sites you might get the idea that you're the worst teacher in the world. The internet abounds with people sharing tweets and posts about wonderful lessons they've just taught, witnessed or learned about in professional development. Sure, the teacher forums rife with requests for lesson ideas and resources but the shared material is always aces. It makes sense, people in the community want to share things that worked for them or things they think will work.

One thing I've learned from teaching is that there's always something new to learn. For the kids, yes, but I'm talking about for the teacher. The other day, I taught a lesson I've taught many times. Find the mode of a data set. That's the problem that they solve but the lesson is really about run time complexity, hidden complexity and using data structures in alternate ways. I blogged about this before so you can get an earlier take there although the code isn't formatted correctly due to blog conversions.