Deborah Tepper Haimo, a highly regarded mathematician and former chair of the Mathematics Department at the University of Missouri-St. Louis, died Thursday, May 17, 2007, in Claremont, Calif. She was 85 and a former resident of University City.

A native of Odessa, Ukraine, Mrs. Haimo was raised in Israel (then the British Mandate of Palestine), and immigrated to the United States at the age of 11.

She earned her bachelor of arts degree magna cum laude in 1943 from Radcliffe College.

She married and followed her husband, Franklin Tepper Haimo, who was also a mathematician, to St. Louis.

Mrs. Haimo taught mathematics at Washington University in St. Louis and Southern Illinois University, while raising her family. After a 10-year hiatus, she resumed her graduate studies and completed her doctorate at Harvard in 1964.

In 1968, Dr. Haimo was hired by the University of Missouri-St. Louis to build its Mathematics Department, and she taught there until her retirement in 1992. Dr. Haimo twice served as chairman of the Department of Mathematics during that period.

Dr. Haimo was a member of numerous professional organizations.

In 1975, she was elected to the Board of Trustees of Radcliffe College, and then in 1990 she was elected to the Board of Overseers of Harvard University. She was an active member of the Mathematical Association of America, and served as president of that organization in 1991 and 1992.

Dr. Haimo retired in the early 1990s to California, where she continued her interest in mathematics education, as a member of the California Department of Education. Her husband died in 1982.

Services were private.

Among the survivors are four daughters, Zara Tepper Haimo of Palo Alto, Calif.; Leah Tepper Haimo of Claremont; Nina Tepper Haimo of Longmont, Colo.; and Varda Tepper Haimo of Lexington, Mass.; a son, Ethan Tepper Haimo of South Bend, Ind.; 13 grandchildren and one great-grandchild.