When mathematician John Ewing started lobbying state governments to adopt a new model for keeping top teachers in the classroom, he anticipated all the usual pushback over funding and resources. One thing he didn’t anticipate was a resistance to the idea in general.

In education right now, “the focus is on everything that’s not working," he says. By contrast, his model "invests in teachers that are doing a really good job.”

In 2009, fellow mathematician and philanthropist Jim Simons called and asked Ewing to help him take over his fledgling nonprofit to provide continuing education for K-12 math teachers in New York City. But the organization, called Math for America (MfA), eventually evolved into a larger fellowship program aimed at cultivating and keeping top science, technology, engineering and math (STEM) teachers in public schools.

It’s an appealing concept at a time when keeping good teachers is becoming harder and harder.

On average, one-third of teachers leave the profession within five years. Burnout is blamed for the short tenure. A recent report from the Robert Wood Johnson Foundation found that 46 percent of teachers say they feel daily stress on a level that’s shared by doctors and lawyers.

When teachers are that stressed, the report notes, it not only compromises their health and quality of life but also adversely impacts their teaching performance. That, in turn, can harm students' academic performance and behavior. The report recommends mentoring programs, social emotional learning and mindfulness as proven ways to improve teacher well-being and student outcomes.

That's where MfA comes in.