If he had asked me exactly how much time students spent on screens across every class, every school, every day, I couldn't have told him. Almost no district in America could.

In Detroit Public Schools, a high school diploma is uniquely tailored to a student's college and career pathways.

The high price tag, coupled with less state funding from students leaving the district, raises questions about whether the academic improvements are sustainable in the long run and whether other districts can afford to replicate it.

Americans' confidence in K-12 education has fallen to its lowest point in nearly 30 years. But the bigger challenge for superintendents is redefining student success.