You could say that once Roger Finnell walked through the doors of Fenwick High School as a freshman in 1955, he never really left.

Sure, he spent four years in college at Loyola University Chicago (class of 1963), but then he was right back at his alma mater.

“I actually had an appointment interview at St. Ignatius,” said Finnell, 80. “But I decided to see if Fenwick had any openings. They gave me an interview and offered me a job before the St. Ignatius interview, so I called and canceled it.”

Finnell retired as a teacher last spring, but he is still active with Fenwick’s math club and math team, still working with the Blackfriars Club on drama productions and, last fall, chaperoned the homecoming dance. He also fills in as a substitute teacher.

“I guess I’m slow to change,” Finnell said. “I still enjoy what I do over there part time. I got involved in more activities as the years went by. I enjoy the daily interaction with the students.”

It was his involvement with the Blackfriars — the school’s drama club — that led the school to name its auditorium after him at his retirement celebration in June 2022. He directed 71 shows, including plays, musicals and the annual student variety show, and produced “uncounted” others, he said.

That honor was helped along by alumni donations, according James Kane, who graduated from Fenwick in 1968. He had Finnell as a teacher for three years “back when he was a young pup,” Kane said, and praised his teaching style.

“I always recall how good he was at explaining complex mathematics to students,” said Kane, who went on to earn a master’s degree in public administration and a law degree. “If you didn’t understand mathematics one way, he would have two or three other ways to explain it until you got it.”

“Over the years, I taught just about every math course that we offer,” Finnell said. “In my later years, I was concentrating on honors and higher-level courses. Years ago, I introduced a set of honors classes for students who finished AP calculus.”

That sequence runs a full three years, meaning students who complete Advanced Placement calculus as freshman will not run out of math to take. There aren’t many such students, but there are some, Finnell said.

Fenwick’s team has been competing in the Illinois state math competition under Finnell’s coaching since it started in 1981 — which makes sense, since a few years before that, Finnell had started the school’s math competition club. The team won its division in the state competition twice, including in 2022.

Finnell was already a veteran teacher when Fenwick started admitting girls as well as boys in 1992. It was a move he was in favor of; in fact, he said, he suggested it to the principal at the time as a way to maintain the school’s enrollment.

“At the time that we were debating whether to go coed, the alumni were against it,” Finnell said. “There was a rumor that the faculty was opposed to going coed, and I said, ‘I’m sure that’s not true.’”

Finnell helped lead a closed-door meeting for faculty on the topic, after which 88% signed a letter of support, he said.

The alumni came around, too.

“Some of them realized it meant they could send their daughters here,” he said.

His teaching career is full of memories, including the time in the early 1980s when a candidate for president of the student council campaigned on a promise to bring Otis Day and the Knights of “Animal House” fame to the school. The student won, and with some hefty donations from parents, the band came and played in the gym.

“I was up on the balcony, keeping an eye on things, and everyone who had anything to do with Fenwick was there — students, parents, faculty,” he said. “The band played ‘Shout’ as an encore, and I remember watching everybody in the gym dancing.”

For 33 years, until 2017, he led a student trip to London and Paris over spring break. For a few years, the group got a behind-the-scenes tour of the U.S. embassy in London; a former student was working there, writing speeches for the ambassador.

For many of those years, the group saw “Les Miserables” in the West End. To this day, his favorite Fenwick production was “Les Mis” in 2010; several of the cast members went on to perform professionally.

Another former student, Patrick Creadon, ended up as a prominent documentary filmmaker, and thanked Finnell in the credits of his 2006 film “Wordplay.”

“It was playing in Chicago and I had four people call me in one day to ask how that happened,” Finnell said.

Finnell keeps up with many of his former students, including Kane. While he never married or had children of his own, he said, “I can claim tens of thousands of children.”

Those are his students, people like Kane, who donated not only to have the auditorium named for him but also gave to a fund to refurbish it.

Kane’s favorite memory of Finnell?

“When I was a senior, I had a date with a girl, and I really wanted to impress her,” Kane said. “He offered to lend me his brand-new car. What kind of a teacher does that — hands the keys to his new car to a student who wants to go on a date? He did. I brought it back in one piece, too.”