Donato “Dan” DeFelice was a “natural” when it came to teaching.

Because Mr. DeFelice was one of the most popular and beloved math professors at Duquesne University for more than four decades, it wasn’t unusual to see students lined up outside his office, waiting for their turns to speak with him, a colleague said.

“He had a tremendous love of teaching and he was one of the best teachers in the department — and probably one of the best teachers ever,” said Patrick Juola of Whitehall, a Duquesne computer science professor. “He really, really cared about his students. He had a wonderful classroom persona and he had tremendous patience with the students.”

“Some people are very fortunate to do something they like for work, and some people are really fortunate and do what they love to do, and that was my father. He was a natural — he loved to teach,” Mr. DeFelice’s son, Dan DeFelice of Murrysville, remembered.

The elder Mr. DeFelice, of Banksville, died Tuesday of pneumonia. He was 88.

He grew up in West Aliquippa and graduated from St. Veronica Catholic School in 1948.

He went on to the University of Pittsburgh, where he earned bachelor’s and master’s degrees in mathematics before joining the faculty at Duquesne in 1954.

At around the same time in his life, Mr. DeFelice met Mary Ann Sakal when they joined the same bowling league.

“She caught his eye,” Mr. DeFelice’s son said. “And he offered to give her and a girlfriend a ride to bowling.”

The couple married 63 years ago.

When he started at Duquesne, Mr. DeFelice was one of only two professors in the math department, his son said.

“Duquesne was a much smaller school then,” he said. “He and the other professor took turns chairing the math department.”

His father won the admiration of his students by giving them partial credit on exams and by testing them on the same subjects repeatedly, until they knew the material, his son said.

“He used to say, ‘You want to know what you don’t know,’” Dan DeFelice recalled. “He wasn’t an easy teacher. He was tough but he was really fair and that’s what the students liked.”

In 1974, the elder Mr. DeFelice was elected outstanding teacher of the year by the university faculty senate, and he was recognized with the President’s Faculty Award for Excellence in 1991.

Mr. DeFelice retired in 2000, after teaching for 46 years.

“He was the longest-tenured teacher at Duquesne at the time he retired,” his son said.

Because Mr. DeFelice was one of the few professors without a doctoral degree, there was some question over whether he should receive the honorary title of professor emeritus upon his retirement, Mr. Juola recalled.

“I am very proud to say that we in the department fought the administration on that issue and we won,” Mr. Juola said. “I am very proud of that because it was a mark of the respect that he was held in by his peers.”

Mr. DeFelice was an ardent sports fan as well, especially for Duquesne teams, his son said.

“He was a sports nut,” his son said. “He was so loyal to Duquesne — I figured that he has been to over 1,000 sporting events over his years at Duquesne. He went to everything — football, basketball, girls basketball and even swimming. A lot of times he would have students who played and he wanted to be supportive.”

His five children also loved sports growing up, Dan DeFelice said.

“Our car never sat still. We were always going someplace,” he recalled.

When his son joined the Duquesne club football team as a linebacker, the elder Mr. DeFelice was bursting with pride.

“He was in his glory,” his son said. “He and my mother drove 14 hours to Lowell, Mass., to see me play in the 1978 championship game.”

For more than 30 years, Mr. DeFelice also served as a choir member at SS. Simon & Jude Church in Scott.

“He was a very religious man,” his son said. “His faith was very important to him.”

Dan DeFelice said he would miss his father’s joyful nature and love of life most of all.

“He was such a fantastic dad. He was very loving,” his son said. “He used to draw a smiley face and he would write ‘Have Fun,’ underneath it every Friday on the chalkboard for his students. He always wanted everyone to have fun.”

In addition to his wife and son, Mr. DeFelice is survived by three daughters, Betsy McCauley of Peters, Kay Ziesche of Redondo Beach, Calif., and Ann Szurley of Wexford; another son, Tom DeFelice of Bethel Park; 14 grandchildren and two great grandchildren.

A Mass of Christian burial is planned for 10 a.m. Saturday at SS. Simon & Jude Church, 1607 Greentree Road, in Scott.

The family suggests memorial contributions to a charity of your choice.

Janice Crompton: jcrompton@post-gazette.com.

First Published: February 17, 2019, 9:10 p.m.