# Polygonal Numbers, Redux

Today I gave my kids a bit of a hint (but not *too* much) on the Polygonal Numbers problem they were working on yesterday. One student said they were working on it at home with their brother. Another one said they were excited to figure this out! They went to it.

All by one group in each class figured it out, with some guidance. It was really great to see. And their excitement when they were able to confirm their answer was ah-maaazing.

I was observed in one of these classes, and the observer said: “It was a real pleasure visiting your class.  I thought the depth of thinking that encouraged from the students was great.  I really liked seeing them grapple with how to structure their series sums and that multiple solutions were encouraged.”

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So many of my kids came dressed up in costume. They were a delight.

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One of my former students gave me a challenging problem from their calculus class: find the $n$th derivative of $e^x\sin(x)$.

I had fun with it! And did get an answer! But it’s so ugly. But I did get to do some nice recursive work on Excel that made me happy. Another student showed me their answer — they stayed up late trying to figure it out — and it is one line and so much more elegant. Hooray for math for fun.

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I went to see the school play (“The Importance of Being Earnest”). It has a 9 person cast, and I happen to teach 4 of the actors. Huzzah! I might have been exhausted, but it was great to see the kids I know in one context be kids in another context. Plus, I like white aristocratic humor.