IM was the second charter school founded for low-income D.C. students by KIPP, the Knowledge Is Power Program. KIPP had gained a national reputation for math instruction. The KIPP leaders in D.C. had good reason to think, as they told Suben, that “we have math pretty much figured out.” Suben, 23 at the time, still thought she could do better. She told her supervisors she was going to produce her own fifth-grade math curriculum. A year later, her students achieved the largest one-year math score jump ever seen at a KIPP school (or any other school that I know of), from the 16th to the 77th percentile.

Suben said: “My primary goal as a teacher is to help my students understand the reasoning behind math rules and procedures. I have several core beliefs about this: (1) Understanding is constructed by the learner, not passively received from the teacher. (2) Understanding is built by making connections between as many strands of knowledge as possible. (3) Understanding is galvanized through communication. (4) Understanding is only valuable when you reflect on it and question it.”

The core of her method is the workbook she produced last year on the fly. It “lets students build their own notes and create their own examples. It is incredibly active learning,” she said. They were encouraged to write down the meaning of important terms and strategies they used that worked with certain kinds of problems.