Ellen M. Stenson

On 16 May 2026, the summation of Ellen M. Stenson diverged to infinity, even as her corporeal form reached a stationary point – consequences of a sudden, catastrophic brain hemorrhage that unexpectedly struck the retired mathematician and calculus teacher a few days prior. Medical interventions had bought time until both her daughters were able to join her husband at her side, for the conclusion of a life of brilliance and defiance that began 80.9 years ago in Detroit, MI.

Ellen was born to Mary (née Pliska) and Earl Shipley on 16 June 1945; in the following years, she gained three siblings (Rob, Anne, and Bill). After their mother’s death from polio in ’52, the four grew up primarily in boarding schools; despite this challenging childhood, Ellen excelled academically. In an era where naysayers told her outright that studying mathematics was a bad idea for a woman, she skillfully produced proofs to the contrary. Ellen earned her Ph.D. from UMass Amherst studying topological semilattices on the two-cell. Along the way, she met, dated, and wed David, a fellow grad student who luckily managed to pass muster with Charlie, her Siamese. (Ellen explained years later, "I married a man of whom my cat approved.")

After settling in Cleveland Heights, OH, Ellen and David both devoted their professional careers to sharing with others the wonders of mathematics. Ellen adopted the axiom of “have chalk, will travel”; she instructed and inspired students from all ages and levels, all across the region (Case Western Reserve University, John Carroll University, Notre Dame College of Ohio, Ursuline College, Laurel School, the Cleveland Collaborative for Mathematics Education, …). Unconventionally, she gave students her home phone number, so they could call with last-minute homework questions or crises; infamously, she once contacted a class on a snow day to give an assignment.

Relationships with friends and family, both immediate and extended, were very important to Ellen. She assiduously seeded, nurtured, and treasured these throughout her life, with a generosity of spirit that was far-reaching and extraordinarily forgiving. Ellen and David racked up countless miles of road trips to spend quality time with friends and relatives; they cared for David’s mother in her 70s and early 80s; they were weekly attendees at Christ the King Church until the end of the parish’s lifetime; and for many years they served as the designated picnic-area stake-outs for the annual Konorosky family reunion.

Daughters Eve and Kate joined the family in ’81 and ’83, respectively. In parenting, as in all aspects of their 56.9 years of marriage, Ellen and David made an incredible team, suffused with love and understanding, humor and devotion. Although Ellen had to admonish her spirited firstborn or her sassy secondborn more often than she might have preferred, she gamely derived solutions to the challenges of motherhood with skill and aplomb. In addition to producing two adventurous, independent daughters who themselves went into STEM, Ellen also bequeathed to them (and, in turn, to her grandkids Vera, Noel, and Dominick) many of her affinities – e.g, logic, puzzles, and problem-solving; cats, dragons, and fantasy; mystery stories, theater outings, photography, and art; cooking, baking, and so much more.

To commemorate her life and legacy, we will be planning a “Celebration of Ellen” (remembrance gathering) within the coming months. For more information as the details solidify, and/or if you have any stories, quotes, photos or other memories of Ellen you’d be up for sharing with us (publicly or privately), please write to us at [email protected].

quo erat demonstrandum