Education needs generalizable models to scale up evidence-based practices and programs and longitudinal research evaluating the persistence of the effect of their implementation. This is particularly important given the "deep, systemic incapacity of U.S. schools, and the practitioners who work in them, to develop, incorporate, and extend new ideas about teaching and learning in anything but a small fraction of schools and classrooms." The authors synthesized research to create a model called TRIAD (Technology-enhanced, Research-based, Instruction, Assessment, and professional Development) for the scale of successful interventions. The specific goal of the implementation of the TRIAD model was to increase math achievement in young children, especially those at risk, by means of centering aspects of the curriculum--mathematical content, pedagogy, technology, and assessments--on a common core of learning trajectories. Results indicate that TRIAD was effective during the treatment period. The TRIAD implementation included a complete intervention in pre-K, and the impact was strong at pre-K. The TRIAD follow-through component was important for persistence of effects. The fact that at least some effects last for African-American children 3 years after the end of all interventions support the need for continued follow through interventions in mathematics for at-risk children. Tables and figures are appended.