Joel Rose, a former teacher, and Chris Rush, a technology and design expert, are the brains behind Teach to One 360, which is based in New York. When Mr. Rose first started teaching fifth grade in Houston in the 1990s, he was stunned by the number of students whose math skills were two or even three grade levels behind. “Some students were as low as the second grade, and other students as high as the eighth grade, and others in between,” he said.

This one-size-fits-all system is broken, he said, adding, “It is wildly outdated.”

So, in 2009, while working for the New York City schools chancellor, Mr. Rose partnered with Mr. Rush to create School of One (later renamed Teach to One 360), a technology driven math program for students in grades five through 12.

Here’s how it works: Students take a 90-minute MAP test, which is a standardized test measuring math skills, and a 60-minute diagnostic test to determine gaps and strengths. The program then uses algorithms and machine learning to identify problem areas and strengths, and creates a personalized daily lesson or “playlist.”

It also chooses the modality, or teaching method. Some may get their lesson through a traditional teacher-led class; others will work in small peer groups collaborating with students who are at a similar skill level; and others will work independently, using online interactive videos, games and math programs. Each student is assigned at least two different modalities a day, and a team of at least four math teachers oversees the program.

At the end of the day, students take a five-question quiz, and the algorithm uses the results to determine the next day’s lessons.

The program was rolled out to 1,500 students in three public schools — one each in the Bronx, Manhattan and Brooklyn — as a pilot project. In 2011, Mr. Rose spun off the program into a nonprofit firm, called New Classrooms, and renamed the program Teach To One.