The Roots of the Equation

One of the best things about being a math teacher, as opposed to a mathematician, is that because I have to think about how to explain a concept to people who don’t get it, I have to think about concepts in different ways than I ever have before. So I often make connections that maybe I should have already made, but hadn’t, and I see the beauty of the conventions and connections of mathematics.

Today I was musing about the use of -1 as an exponent to give us a reciprocal, because my next lesson is about Egyptian Fractions, and so their fractions are basically the number with an inverse symbol, which we still use, -1. And then I thought, well, yes, that is our inverse symbol, for functions too. Of course, that makes sense. But the clearness and uniformity of it seemed new. So often we learn about things in math in such disconnected ways, so it’s just “Here’s one use for the -1. Here’s another. That’s the way we do it.” But not why it’s the same for both.

And I get these realizations all the time. At least 5 last year. (I think another I had had to do with FOIL.) I hope I keep getting them. But the next step is, of course, to figure out how to let the students get them. Because then, I think, they won’t hate math so much.