In high school, there are always teachers whose names alone strike fear in students' hearts, and teachers whose names elicit high-fives from the jocks and back-row kids.
And then, if you're lucky, you've got a handful of teachers who turn all the stereotypes on their heads: teachers who make college-level courses like calculus fun; who pass out Nerds candies to students who catch mistakes; teachers who write hundreds of college recommendation letters because they know their students intimately.
Enter Eric Yarborough: the 68-year-old energetic, charismatic, math enthusiast who loves his students as if they were his own children.
Yarborough has been teaching math at Providence High School for six years, but he started leaving his imprint many years before that.
The son of a Baptist minister, Yarborough graduated from Taylorsville High School in North Carolina in 1951.
After attending junior college at Wingate University, he graduated from Carson-Newman College in Tennessee with a major in math and a double minor in physics and English.
Yarborough had considered teaching since he was a child.
"Even when I was in eighth-grade algebra, I found myself being able to answer students' questions and ... explain to the teacher what other students were asking," he said.
After graduating from college, Yarborough earned a master's degree in a year-long mathematics program at Louisiana State University and then returned to teach math at Wingate. Three years later, he left to serve in the Vietnam War.
He returned "a troubled young man," unsure what he wanted to do, so he walked into an education center and a woman with Charlotte-Mecklenburg Schools recruited him to work with a special program for students struggling in school.
It wasn't long before Yarborough was hired by legendary principal D.K. Pittman at East Mecklenburg High School.
He spent 14 years at East Mecklenburg before he began teaching at a small Christian school in Monroe through Sunset Park Baptist Church (no longer in existence).
In 2005, Sue Sams, who built the math department at Providence and had worked with Yarborough at East Mecklenburg, convinced him to join her at Providence.
"I called Sue Sams and told her I wanted to get back in public education, and she said 'Oh yes, please come to Providence ... don't go anywhere else in the city,' " said Yarborough.
As far as numbers go, Yarborough has a 90 percent passing rate on the Advanced Placement Calculus BC exam, which gives students college credit for Calculus I and II.
But it's hard to quantify the influence Yarborough has had on students.
Yarborough and his late wife, Loretta, didn't marry until they were in their mid-30s, so they never had children. Yarborough's students became his surrogate kids.
"They come in not really liking math, and they come out loving it," said junior Jack Mazzulo, 17.
"His class is a lot different than our other classes," said junior Ashley Reid, 16. Reid recently participated in a math competition at UNC Charlotte with Yarborough and got accepted to Governor's School of North Carolina this summer thanks to his prompting.
One year, the senior class voted him the teacher who had influenced them the most in their high school careers.
Yarborough was recognized at the Charlotte Bobcats home game on March 9 as being one of four finalists for the Carolinas Champion 2011 competition recognizing outstanding CMS teachers. At the April 9 game, they'll announce the competition winner, who will get a 2011 Hyundai Sonata.
Providence junior Quinn Holmquist nominated him.
"He's my favorite teacher, and I look up to him as a person," said Holmquist. "People usually try to get as far away from the classroom as they can, but people hang out in his room."
But how does Yarborough make calculus fun?
Well, when the class learned the Fundamental Theorem of Calculus, Yarborough planned and officiated a wedding to celebrate the union of integration and differentiation.
He offers tutoring in the morning, before school starts at 7:15 a.m. and after school's out at 2:15 p.m. The day before a test, he'll stay until the last student is ready to leave, which is often at 5 or 6 p.m.
Yarborough said he's not up on pop culture and what 21st-century teens like to do and watch. But somehow he and the students still share a special connection.
"One thing I try to do is show respect to the students and treat them like adults, knowing full well they're not really adults - they're teenagers - but they respond to that. I think the worst thing a teacher could is have an adversarial relationship between them and the student.
"My kids like to say they're some of the smartest and brightest around, and I teach students who are a lot smarter than I am, as far as intelligence goes," he continued. "But I tell them I've got a little experience on them and I'm their ticket to passing the AP exam. They love me and say they respect and honor me. It puts a lot of pressure on me to give them what they need. I don't want to let them down."
In November 2009, Yarborough's wife of 31 years, Loretta, found out her recurring breast cancer had metastasized to her lungs. Yarborough spent Christmas break and all of January by her side.
Loretta lived 67 more days and passed away Feb. 3, 2010.
"The kids were so gracious," said Yarborough. "They wrote me notes, sent me flowers, came to the viewing. They've been so loving and supportive."
But the students worried their teacher wouldn't come back, that he would decide, after nearly 42 years of teaching, it was finally time to hang up the hat.
"The whole school talked about it - 'Is he coming back?' " said Holmquist.
But one morning, three weeks later, the students saw Yarborough standing outside his first-floor classroom.
At the end of every year, Yarborough asks his students for an evaluation - what did they like most about the course, what did they like least.
"A couple of the students said the worst part of the year was when I left, and the best was when I came back," said Yarborough.
Yarborough credits his fellow teachers, the administration and the strong support of parent volunteers with why he's able to teach effectively. And most of all:
"I am what I am by the grace of God," Yarborough said. "If I have any success with these kids, it's because the Lord is doing it through me. ... If the Lord put me there, he had something for me to do."