1. Will We Ever Use This?
“Mr. Hasan?” he asked from the back of the room. “Will we ever use this?”
This is a frequent complaint in math classes. To my everlasting frustration, it’s a common refrain. Frustrating because, do they ask this of their English teachers? Their Theatre teacher? History? Band? Economics, for heavens sake?
Of course, that’s not how I answered. I didn’t say that, because in this particular case, his polite, diplomatically phrased question was a good one.
I had given the pre-AP kids a really hard homework assignment (finding zeros of polynomials, including complex conjugate pairs). The four problems were long, tedious, and difficult. The algebra for one of them filled a full page. It must have seemed like busy-work.
I conceded his point and explained my rationale.
“I know these were hard,” I said. “I assigned them because there are some things in life are just plain hard. Some things require paying attention to detail. Cooking. Changing a transmission. Installing a downspout without cutting into the plumbing that runs behind it.”
(Just kidding. I didn’t go into my own downspout shame.)
“I designed these problems precisely because they are hard, because they are tedious, because you won’t get the right answer unless you are neat and careful.”
I stopped for a second and looked at them.
“We talked about this at the beginning of the year. This class isn’t just about the math. It’s mostly about teaching you to think clearly and communicate well. And for those things, you need to sweat the details. These problems teach you that.”
I waited a second and then looked back at the boy who had asked the question.
“Does that answer make you angry?”
“Kinda,” he said.
“That’s fair,” I said. “But that’s the best I can do. And it’s the truth.”
2. Logarithms in the Real World
We started with logarithms a few weeks ago.
One of the challenges of teaching logarithms is that the notation a bit odd and logs just seem… seem so… irrelevant. Certainly none of my students has seen much less used a slide rule. With the calculators we have on our phones, logarithms seem about as useful as the trig tables in an old CRC Handbook.
I anticipated the “How are we going to use this?” question. So I put together some problems in that showed real-world examples of logarithms. The Richter Scale. Decibels. Cents…
Wait. What? Cents? Yes, cents.
Not cents as in “dollars and cents” but a measurement used to quantify relative pitch in music. I had stumbled across cents when I was putting the lesson together.
While we were going over the problems, I stopped and looked up.
“I had never heard of cents. Have any of you?”
The percussionist in the front row nodded. He said they use it when they tune.
And there you have it. Logarithms in the real world.
3. My Cornet
“I am so ashamed,” I said. “I mean, I was in band, and I’ve never heard of cents!?”
“You were in band?” one of the kids asked. One of the others told her that they all knew I had been in band.
“Yes,” I said. “My cornet is in the band hall.”
“Wait, what? Why is… your cornet in the band hall!?”
I started to explain how I had given my old high school cornet to the band director.
“Oh yeah,” one of the band kids said. “Lucy was playing his cornet yesterday.”
Lucy is in a different period later in the day. When that period rolled around, I walked up to her.
“Lucy, I hear you are playing my cornet.”
She smiled and her eyes sparkled.
“Yeah,” she said. “It’s so much easier than a trumpet.”
So you see? Logarithms will take you far.