This four-year program of Pri-Math II is designed to transform the 1990-93 NSF-funded, school-based Pri-Math (I) project into a district-level leadership model to improve mathematics education in the primary (K-4) grades. During its first two years, PriMath II will work with school systems to develop individual, long-range improvement plans. Ten participating teams will each include up to four (K-4) classroom teachers or specialists selected from Pri-Math I participants + a district-level administrative person. Those teams will in-turn select supporting teams to enroll in the second two years. Thus 56 lead teachers and 33 administratives will be involved directly to reach 1668 teachers indirectly by peer teaching. Project activities will occur in 4 settings during each of the 4 years: 4-week summer institutes, 8 school-year seminars, 4 school-year visits by the PD to participant classrooms, and among participants within their schools coaching peers plus conducting inservice to articulate/implement system-wide plans. Mathematics content and pedagogy is integrated throughout, with summer mathematics content courses being Geometry/Spatial Sense, Functions & Proportionality, Number Systems & Number Sense, and Data Analysis.