[1] Ross returned to Odesa, Ukraine with his mother in 1909 for assistance from her extended family,[1] and stayed once World War I and the Russian Revolution broke out.

[1] As money meant little due to inflation, Shatunovsky was paid to tutor the two boys with a pound of French hard candy.

[1] After negotiating his way home, he worked at a family friend's bookbinding shop and continued to learn English at the Lewis Institute.

[1] Ross married Bertha (Bee) Halley Horecker, a singer-musician and daughter of Ross's Chicago neighbors, in 1931,[1] received a National Research Council Fellowship for 1932,[5] and worked as a National Research Council postdoctoral fellow[4] at California Institute of Technology with Eric Temple Bell until 1933.

[2] Ross moved back to Chicago and led the mathematics department at an experimental school started by Ph.D.s during the Great Depression, People's Junior College,[4] where he also taught physics.

[1] He occasionally worked on proximity fuzes for Stromberg-Carlson's laboratory from 1941 to 1945[1] before accepting a position as head of University of Notre Dame's mathematics department in 1946.

[2] He set out to change the school's research climate by inviting distinguished mathematicians including Paul Erdős, whom Ross made a full professor.

[1] While at Notre Dame in 1947, Ross began a mathematics program that prioritized what he described as "the act of personal discovery through observation and experimentation" for high school and junior college teachers.

[1] In 1957, the program expanded via the National Science Foundation's post-Sputnik funds for teacher retraining, and Ross let high school students attend.

[2] The program lasts eight weeks and brings students with no prior knowledge to topics such as Gaussian integers and quadratic reciprocity.

[2] Though the program teaches number theory, by its Gauss-inspired[6] motto, "Think deeply of simple things," its primary goal is to offer precollege students an intellectual experience[2] as what he described as "a vivid apprenticeship to a life of exploration.

"[9] This emphasis on computation alone too often produces students who have never practiced thinking for themselves, who have never asked why things work the way they do, who are not prepared to lead the way to future scientific innovation.

"[2] First-year students meet daily for lectures in elementary number theory and thrice weekly for problem seminars.

[2] They are encouraged to think like scientists and devise their own proofs and conjectures to the problems posed,[2] which occupies most of their free time.

[8] Ross designed the daily problem sets,[9] and many questions contain his signature directions: "Prove or disprove and salvage if possible.

[2] As NSF support fluctuates, the program has been funded by various means including gifts from donors, scholarships from businesses, a National Security Agency grant, the university, and its mathematics department.

[1][8] The program grew rapidly with input from prominent mathematicians such as Ram Prakash Bambah, Hans Zassenhaus, Thoralf Skolem, and Max Dehn.

[1] Ross left Notre Dame to become chair of Ohio State University's mathematics department in 1963, and the program followed in the 1964 summer.

[10] Ross reached his mandatory retirement from Ohio State University in 1976,[2] when he became Professor Emeritus,[4] but continued to run the summer program through 2000,[9] after which he had a stroke that left him physically impaired and unable to teach.

[8] The Arnold Ross Lecture Series founded in his name in 1993[13] and run by the American Mathematical Society puts mathematicians before high school audiences annually in cities across the United States.