Focus on Mathematics is a partnership seeking to improve student achievement by providing mathematics teachers with the content knowledge and skills valuable in their profession. Centered at Boston University, the partnership includes the Education Development Center, the Massachusetts school districts of Arlington, Chelsea, Lawrence, Waltham, and Watertown; Lesley University; the University of Massachusetts- Lowell; and Worcester Polytechnic Institute. Focus on Mathematics offers teachers solid content-based professional development; provides students with rigorous courses and curricula; develops and supports a cadre of mathematically expert teachers who will share their knowledge with teachers in their districts and students in their schools; and is establishing a community in which mathematicians, educators, and administrators work together with students to put rigorous mathematics at the core of their teaching and learning.