STERLING – For a teacher who will spend 45 minutes scrambling without stumbling, Steve Johnson is looking quite uncomfortable this Thursday afternoon. He’s pinned behind his desk for an interview while his kids … er, sophomore students … enter his accelerated chemistry classroom.

He greets Mitchell Petrosky and a few others, but he’s practically twitching to be at the door. That’s where the chemistry between teacher and student begins.

“I’m out of place,” he says. “Usually I’m at the door to greet them as they come in, and that’s kind of part of building those relationships. Every day you want to make sure your classroom is a safe place for them to learn, and where they can ask questions and be part of it.

“For me, it all kind of starts as they come in the door and you greet them by name. They know you’re going to be there every day and that it’s a welcoming learning environment.”

He has some fun stuff planned. Then the Internet goes down. Minutes before that, he’d shared one of the best tricks he’s learned in 25 years teaching in the district.

“A well-structured lesson usually takes care of any problems you might have in class,” he said. “Make sure you’re fully prepared, you’ve done your homework, you understand the material well, and you’ve got something engaging to keep kids occupied.”

And ... you're on, Mr. Johnson.

It turns out his Internet is fine. It’s the student wi-fi that’s down. So he makes light.

“I’ll just give you all the staff password, and we’ll be good to go. … Yeah, I don’t think we'll do that,” he says.

Humor is a big part of how he relates. Among the safety warnings along the glassware case is one advising students not to wear baggy clothing, with a picture of a student with a raging fire Photoshopped on her sweater sleeve.

He keeps the crowd rolling, and guessing, with deadpan sarcasm.

“We might just have to send everyone home early,” he says.

He keeps things light during some mundane-but-necessary review questions on – gulp – paper and pencil.

“Build those calluses back up,” he jokes.

Then comes the mother of all relatable analogies for high school-level cooks.

The subject is stoichiometry. Johnson could give his students a textbook definition: the calculation of the quantities of chemical elements or compounds involved in chemical reactions. Or, he could use a grilled cheese sandwich.

Guess which one he chose?

Rather than mass and moles and numbers and letters that look Greek to a nonchemistry student, he explains that stoichiometry is like trying to figure out the maximum number of grilled cheese sandwiches that can be made with a specific number of slices of bread and cheese.

Akira Tanton, 15, can’t help but laugh.

“It really does make it much easier to understand,” she says.

“He finds creative ways to put the material into our perspective,” Sebastian Heeren adds.

“He makes it interesting so that we’re into the material,” Mitchell says.

Akira already has her sights set on the medical field – anesthesiology, specifically. So the Next Generation Science Standards – next-level, Common Core-based logic – make her feel like time in class is well spent.

“The examples he gives help me to really understand how it pertains to real life,” she says. “It helps me in other classes, too, not just this class. In math I can now relate it to real-life things. I want to know how it’s going to relate to what I need to do.”

Johnson grew up in Tampico and he and his wife, Marsha, have known each other since kindergarten. So it was serendipitous when they both landed jobs in the Sauk Valley – she teaches in Dixon. Their children, Trevor and Allie, are both in college after going through the Sterling School District – they even had Dad as a teacher.

But then, it feels like all Johnson’s kids … er, students … are family. After class, he’s back to anchoring the door.

“How are those knees doing, Alex?” he asks Alex Commisso, who’s either recovering rapidly or has an incredible threshold for pain. He sprained both of his knees skiing in Utah over winter break. He was wearing a GoPro, and showed Johnson the footage after Wednesday’s class.

“Yesterday after class, he showed me the video footage of trees going upside-down and right-side-up – it looked horrible,” Johnson says.