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Like middle school math teachers everywhere, the seventh-grade math teachers at Middle School 88 in the southern part of Brooklyn’s Park Slope have an impossible job. At this high-poverty school, which not long ago was considered failing, students enter with levels of math skills ranging from kindergarten to eighth grade. How can anyone teach to them all?

Middle School 88 in Brooklyn is part of a broad evolution in teaching math, employing technology to provide each student with a personalized lesson.

Emily Reisman, who’s been teaching math at M.S. 88 for six years, said that until three years ago, the school taught math the way virtually everyone did. “We would create work sheets at different levels,” she said. “For adding and subtracting fractions, we’d create low, medium and high-level activities for kids to do. The lower level was more straightforward, with a picture. The higher level had word problems.”

Math teachers also try to personalize instruction by grouping students by ability and spending more time with groups that need extra help. They have students work together and teach one another. They offer bonus activities.

But none of these strategies allows students to learn at their individual levels. And that is imperative, because math is cumulative: basic skills are necessary for building advanced ones.

The American educational system, then, creates a permanent math underclass. A student who fails at fourth-grade math will be likely to fall further behind each year. If he is missing essential early skills and concepts, he may spend the rest of his years of school learning nothing at all in math.

“For any subject, any room, it can’t be true that one teacher teaching 30 kids is the best way,” says Joel Rose, an education expert who in 2009 worked for the New York City Department of Education. There, he and Chris Rush, a consultant, developed School of One, a method for math teachers to personalize instruction, and brought it into three middle schools.

Rose and Rush then left the city department and established New Classrooms Innovation Partners, a private nonprofit organization that now works with schools to use Teach to One, a program that evolved from School of One. (It’s still called School of One when used in New York City, where the schools do not pay licensing fees since it originated at the Department of Education.). So far, the program is used in only 30 schools in New York, New Jersey, Washington, D.C., North Carolina and Georgia. Results are positive but not uniformly so. It’s a work in progress – but one with great potential.

M.S. 88 has been using School of One in one of the three academies into which it is divided. The program requires a large-upfront investment. The school knocked down three walls to create a giant classroom, and Ailene Altman Mitchell, the principal, said she also spent $140,000 to buy a laptop for each child, along with screens and tables.

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The classroom is the size of four rooms, its divisions marked with shelving and different colored carpet and chairs. When I visited last month, all four seventh-grade math teachers and some aides circulated, teaching 120 students as a team.

As math class begins, students find their names on airport-style monitors outside the room, which tell them where to go. The different areas are named for high schools in Brooklyn. (Peter Russo, the assistant principal, said that last year the school made the mistake of using New York sports teams. They were dropped when this proved too depressing.)

The monitors also tell the students which of several learning modalities they will use. That day, some answered questions at a computer. A few feet away, others did work sheets in pairs. Five students sat at a table with a teacher, solving equations. At one end of the room, Reisman worked with 23 students on a multiday probability project.

Subject matter varied — simplifying equations, subtracting negative numbers, graphing expressions on a number line, and solving story problems about probability.

At one table, Tianna, Romel and Danielle were hunched over work sheets of probability problems involving gumballs. Work sheets also offered wrong answers, and asked students to identify the mistakes that led to them.

The three were discussing the errors, and endorsed the method. “It engages kids,” said Tianna. “You don’t get bored listening to the teachers. And the computers make it more fun.” Romel and Danielle said they liked working in groups.

M.S. 88 is part of a broad evolution in teaching math, employing technology to provide students with a lesson personalized for each.

The first step, now widespread, was the digital lesson, usually a computer game or video. The best-known web provider, Khan Academy, is free. But there are many other sources of digital lessons, from pricey packages created by education companies to rudimentary videos that teachers make at home.

Computers can also administer and grade math quizzes; some choose the next question depending on how the student did on the previous one. If a student tests her mastery with a short exit quiz every day at the end of the lesson, the teacher and student can know quickly whether the student is learning, and how the student learns best.

School of One has both components. New Classrooms has a library of 12,000 lessons, some created by its staff, but most bought à la carte from companies like Pearson and IXL. About a third are online, and the rest are taught live. And every math class ends with each student taking an online quiz that tests whether she has mastered today’s lesson.

But the next step is the real innovation: the educational equivalent of an air traffic control system. Each student’s daily exit quiz is fed into an algorithm, which produces the next day’s schedule for each student and teacher. (Teachers get a preview, and can override the schedule.) If a student has mastered a skill, on to the next one. If not, she gets another day’s instruction, this time through a different modality. (The algorithm is aware of which modalities work best for her.) It’s an enormous departure from traditional teaching.

Justin Reich, a scholar on educational technology at Harvard’s Berkman Center for Internet and Society, said other digital learning platforms try to integrate all the pieces, but School of One is the most comprehensive. “Technology has proven to be good at assessing students’ computational abilities very, very quickly,” he said. “But we’ve had a lot of difficulty translating that model of what students know into actionable information. The information we give teachers is either too coarse or too fine. It’s either ‘Johnny can’t do math’ or ‘here are 186 characteristics on seven dimensions of proficiency’ and the teacher says ‘I can’t look at all that.’ The value proposition of School of One is: by telling you what the next instructional step is, we’ll help you thread between that.“

Many brands of technology save teachers from spending time making up and grading tests. School of One also regroups students and matches them with the just-right lesson. “In a regular classroom, you do the best you could,” said Reisman. “But this does it every night for you.”

Is School of One a timesaver overall? Not necessarily, said Yaron Bohbot, M.S. 88’s math coach, and a former coach with New Classrooms. The collaboration School of One requires takes extra time, he said, but teachers can spend less time on rote work.

Related More From Fixes Read previous contributions to this series.

Although New Classrooms is one of the few nonprofits in the field, School of One is expensive. (A federal innovation grant still pays for the program in New York’s schools, but that ends this year.) Mitchell estimated that School of One costs some $40,000 a year more than other math tech programs, or about $100 per student. Teachers must also learn to use the program, in an after-school simulation in the spring and training during the summer.

That cost is well worth it if School of One is a much better way to teach math. But we don’t yet know if that’s the case. New Classrooms funded a study carried out by Douglas D. Ready of Teachers College, Columbia University. It evaluated students using a comprehensive test called Measures of Academic Progress, which many schools take at the beginning, the end and sometimes the middle of the school year.

Ready found that in their first year of using School of One, the seven New York City schools made progress statistically similar to the national average. The second year, however, School of One did much better. It added eight more schools, and the collective gains for the 15 schools were 47 percent higher than the national average. They were also highest among the worst-off students, which is exactly what you want to see. M.S. 88 did slightly better than the national average in math improvement the first year, but in the second year did 60 percent better. That’s an extra six months of learning.

Why did schools do better the second year? New Classrooms is always changing the program, and might have improved something important. Also, everything in teaching improves with practice.

School of One isn’t the only program to show impressive results when compared to a national average, said Reich. “But the gains may be in part due to the fact that these are schools that decided to put a lot of time and money into improving their math teaching,” he said. These same programs usually show less impressive results when tested in a randomized controlled trial that compares math gains in schools that use the program to gains in others that want it but will get it later.

The teachers who use it at M.S. 88 (obviously far from a random sample) said they like it. Reisman said her students are more engaged and have more math confidence, and that students sometimes find a learning modality that works where others have failed.

Andy Zimmerman teaches seventh-grade math in all three M.S. 88 academies. He uses School of One in one of them, but has adapted its ideas for use in his other classrooms — sewing together various pieces of technology, something Mitchell called “Frankensteining.”

“Seeing that done in the School of One model, I’m able to wrap my head around it,” said Zimmerman. “But in a classroom where you use lots of different tools, there’s an organizational challenge. For example, Khan and IXL aren’t made to talk to each other.” But School of One, which uses both, “has the value of making using both of these tools simultaneously easier,” Zimmerman said. And only School of One, he said, recommends the appropriate next lesson for each student and organizes the classroom accordingly.

Critics ask a good question: Why should a school try an expensive, disruptive high-tech platform that’s still unproven? The answer is: in order to prove it. School of One takes comprehensive advantage of technology in ways that let teachers concentrate on teaching. That’s worth getting right. There may be ways to make it cheaper and more effective, but only through further experimentation. As for being disruptive, does anyone defend the current system? “We’re not aspiring to create the least disruptive program,” said Rose. “Our goal is a model that works.”

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Tina Rosenberg won a Pulitzer Prize for her book “The Haunted Land: Facing Europe’s Ghosts After Communism.” She is a former editorial writer for The Times and the author, most recently, of “Join the Club: How Peer Pressure Can Transform the World” and the World War II spy story e-book “D for Deception.” She is a co-founder of the Solutions Journalism Network, which supports rigorous reporting about responses to social problems.