My students hump the midterm. It wasn't just bad, it was historically bad. An epic humping. Two-thirds of the class got below 50 percent.

You struggle over things like this as a teacher.

Was it my fault or theirs?

They haven't learned anything– should I start again from day one?

But the more immediate question is how to address the class. Should I yell and fume and try to light a fire under their asses, or should I be understanding of their toils, and remind them that they can still bring their grades up on the final.

Everyone has a bad day, after all.

I decide to keep it light.

"Wow!" I say, as I go into class, with a gleeful smile "You guys sure humped the exam. Never seen a shit show like that."

It doesn't come off as playful as I intend it.

I put the exams down on a desk.

"But don't worry, kids." I continue, "It doesn't mean you are shit. Everyone has their strengths and weaknesses. Algebra is for some people, and not for others. We can't all be great at everything. Look at me. I can't roll my R's. When I try, my lips just get all tickly."

I go on trying to roll my R's: "Round and round the ragged rock the ragged rascal ran."

"Come on! Try it. Round and round the ragged rock the ragged rascal ran"

"Repeat after me!" I yell, "Round and round the ragged rock the ragged rascal ran"

Some of them start repeating.

"Wonderful!" I yell, and the students look more alive than I've seen them all semester.

"Now try this." I say, "Erre con erre cigarro, erre con erre barríl, rápido corren los carros cargados de azúcar al ferrocarril."

"Ear corn ear..." they repeat, with wonderfully rolled 'R's.

"Look!" I exclaim, "You roll your R's like Spanish Pirates!"

The students want more, but I realize that I am going a bit off track, and so veer back to the test.

"You're great at rolling your 'R's." I say, "Now if you can just get that good at algebra, you'll do great."

The students are clearly comforted by my pep talk, invigorated by it. And what is a mathematician's job if not making people feel okay about their inadequacies.