This publication focuses on research designed to improve adolescents' learning of mathematics. It helps school leaders and faculty members work collaboratively to develop schoolwide or districtwide plans to improve math learning by incorporating research-tested practices into instruction, assessment, professional development, and school structures to support struggling learners. The intended audience includes middle and high school teachers and administrators, leadership teams, special educators, curriculum specialists, district supervisors, superintendents, and school board members, as well as parents and community members.