David C. Kelly was a professor of mathematics at Hampshire College in Amherst, Massachusetts. Kelly founded the Hampshire College Summer Studies in Mathematics program.

Early life and education

Kelly was originally from New Rochelle, New York, but moved frequently as the child of a military father.

before joining Hampshire College in 1970 as one of its founding faculty members.

He died on June 10, 2025.

Yellow pigs and 17

During his time at Princeton in the early 1960s, Kelly and fellow student Michael Spivak created "Yellow Pig's Day," an annual celebration of mathematics and the number 17. He continued to be involved in the organization of the holiday each year, commemorating the day with food, songs, a reunion, and mathematics. He was quite familiar with many of the properties of the number 17,

Legacy

Kelly was well known for his inquiry-based teaching style. He often used the phrase 'Interesting, if true' to encourage students to investigate mathematical claims. Through his leadership at HCSSiM, he fostered a unique mathematical community that influenced generations of students.

Hunting Yellow Pigs documentary

In 2025, the feature-length documentary Hunting Yellow Pigs was released. Directed by Ming-I Huang and executive produced by HCSSiM alumnus Jon Roberts, the film explores the unique community and "questions-first" philosophy David Kelly established at Hampshire College. It features interviews with prominent mathematicians and alumni, including Steven Strogatz,

References

  • Faculty biography
  • David C. Kelly at Hampmedia
  • Hampshire College Summer Studies in Mathematics