PORTLAND — Russell Rainville, 70, of Industry, died of a sudden illness on Wednesday, May 21, at Maine Medical Center.

Russell was born in Manchester, N.H., the son of William and Helen Rainville. He received his master’s in mathematics at the University of New Hampshire and earned his Ph.D. in mathematics in 1971, also from UNH. Russell was a professor of mathematics at the University of Maine at Farmington from 1977 to present. He was chairman of the division of mathematics and computer science for 10 years.

Russell is survived by his wife, Gail Lange; brothers, Bill and Paul; brother-in-law, Louis Lange; sister-in-law, Brenda Lange-Gustafson; nephews, Brandon and Matthew; and many cousins.

He was predeceased by his parents and his brother, Roy.

Russell was a loving husband to Gail. They worked together in many ways, including teaching and researching in the mathematical and computer science fields, biking and ocean kayaking, and traveling to places such as England, France and Italy.

Russell had a fantastic sense of humor, which faculty and students alike enjoyed. Russell spent hours working with students in his office, if needed, to explain a concept. He was very diligent in his preparation of projects and other assignments for his students. He had a gift for teaching the problem-solving course, in which each student would pick a unique problem, either suggested by Russell or by them. He had a wonderful way of giving them help and yet allowing the students to solve their problem.

Russell was exceptionally intelligent and this shone through in all his mathematical conversations with faculty and students. He encouraged creative work and research by running the division’s Mathematics Hour, which sponsored faculty and student talks. He was also dedicated to improving the core section of the university’s requirements, offering detailed and applicable solutions.

Russell was a fine artist, specializing in mathematical sculpting. Some of his work is on campus, including on the front lawn of Brinkman House. He was the curator for the 150th anniversary celebration in mathematical art and the artwork was exhibited in the Emery Arts Center.

Russell had a great joy of life in everything he did. He was extremely curious and was a problem-solver. Russell was a member of the following societies: Mathematical Association of America, the Institute for Operations Research and the Management Sciences and the Society for Industrial and Applied Mathematics. He was a member of the Maine Civil Liberties Union and always carried a copy of the U.S. Constitution with him.

Condolences may be sent for the family at www.adamsmcfarlane.com.