Today, far too many students see mathematics as a subject to be endured, rather than a subject of real-world importance and personal value. That doesn't have to be the case. When teachers use student-centered techniques to engage students in more active and authentic ways, they can transform math classrooms into lively learning environments in which students take charge of their own learning, collaborate with others, persist in solving complex problems, and make meaningful connections to the world around them. Through such experiences, students may come to appreciate mathematics as a discipline that enriches their lives and their understanding of the world. While a growing body of research supports many of the principles of student-centered instruction, there is still a great deal to learn about how such approaches enhance student learning in mathematics. Recent calls for strengthening the STEM workforce and for more rigorous K-12 standards via the Common Core State Standards have placed increased emphasis on developing higher-order thinking and problem-solving skills in high school mathematics, heightening the need for more information about how teachers can effectively engage students with math content. The American Institutes of Research (AIR), with support from the Nellie Mae Education Foundation, conducted a study of highly regarded high school math teachers to expand the research base in two important ways. First, rather than assuming student-centered instruction is a monolithic construct, the team used a case study approach to provide rich descriptions of how the approach plays out in several classrooms, taking into account how teachers' personal philosophy and the school'sinstructional context might influence their practice. The case study also provided insights into students' perspectives on different approaches to mathematics instruction. Second, the researchers look across a larger sample of classrooms to determine the effects of varying degrees of student-centeredness on students' engagement with learning and their problem-solving skills. This brief offers highlights from the study's design and findings. Readers are encouraged to access the full paper for more details.