This is my contribution to the Convention of Mathematical Flavors organized by @samjshah2. He put a call out for presenters to ponder the “mathematical flavor” of their classrooms

How does your class move the needle on what your kids think about the doing of math, or what counts as math, or what math feels like, or who can do math?


Most of the time, I can’t keep a straight face. I chuckle while retelling stories. I burst into wide laughter when my kids do something adorably embarrassing, like when my 2 year old announced to an elevator of people that it “stinks like a bumblebee in here.” I smile nervously when I’m caught guilty of something — forgetting to fill the car with gas, or eating the last bite of ice cream. I would make a lousy poker player.

But I trained myself to keep a straight face when a student is revealing their thinking to me.

I don’t think it was easy at first, although I have blocked out most of the memories. I think I had a lot of tells, especially when I was in my student teaching internship. I imagine that, when listening to a long and incorrect explanation, I knit my brow, and asked follow-up questions like, “wait, are you sure? Remember that 5 x 5 is bigger than 10?” As if that last one is a question at all.

I wanted to badly to be helpful, at all times, that I cheated students out of their own thinking.

No one encouraged me to change. My students were happy — and accurate on the page. Still, allowing students to rely on my facial tells felt incongruous with my values. I wanted students to think through problems. I wanted students to trust their own thinking. I wanted the learning to be authentic, which meant that students needed to be able to answer questions without reading my face like an answer key. I knew that the most important thing we can do — for the student, for our teaching, for the learning — is to listen openly and honestly. This meant not distracting anyone with the twitch of an eyebrow or a well-intentioned frown.

Training myself to keep a straight face while listening to a student was like learning how to walk. It took a lot of effort in the beginning, and I can’t really remember any of it. I just knew it was important. So I practiced.

…and practiced.

…and practiced.

I think I bit my lips at the beginning, a nervous habit. It was better to look a little silly than to allow my mouth to curl up or down, giving away my response. After a while, I was able to relax the muscles in my face. All of my energy could go into the real work — the work of listening.

“Is it 10? 11? 9?” I remember a second grader asking with increasing urgency and agitation. “COME ON. I CAN’T TELL FROM YOUR FACE.”

I smiled. “I know.”

It felt natural… easy. I didn’t care that it annoyed him, because it meant that that I had created incentive for this student to employ his mathematical reasoning. It’s not easy to learn to trust your own thinking, just like it’s hasn’t always been easy for me to keep a straight face while listening.

I spend a lot of time listening to kids: valuing what they have to say, and encouraging them to persevere. Maintaining a neutral expression allows me to listen. It allows students to be vulnerable. It doesn’t mean that I never smile, just that I don’t use smiles to signify correctness. Keeping a straight face is at the cornerstone of what I do, and what I believe about my role in the classroom.



The featured image of this blog post, of the comically large smile, is a screen shot from a video of me teaching in 2005. I told you… couldn’t keep a straight face.