This proposal in the area of Teacher Enhancement is a 51-month Local Systemic Change (LSC) Project involving 222 middle school teachers of mathematics in four New York City community school districts (CSD #5 in Central Harlem, CSD #9 in the South Bronx, CSD #13 in Bedford Stuyvesant, and CSD #19 in East New York). The project is a collaborative venture involving New Visions, the New York City Board of Education, and City College of New York. The overall goal of this project is to change the way in which New York City teachers in truly needy areas teach mathematics, in order to significantly strengthen what and how middle school students learn mathematics. The centerpiece of the project is the generation and support of biweekly, school-based teacher study groups, led by specially trained teacher leaders. The project will support the New York City Board of Education's implementation of the New Standards in Mathematics, which began its implementation cycle in the fall of 1998. The project's participating schools will be using the Mathematics in Context and Connected Mathematics middle school mathematics curriculum materials. The (MS)2 Project has the support and a close working relationship with the New York Urban Systemic Initiative.