This report summarizes the results of a scale-up project funded by the Institute of Education Sciences in 2006. "Scaling up TRIAD: Teaching Early Mathematics for Understanding with Trajectories and Technologies" was a project that took a preschool mathematics intervention to scale across three sites, following children from their Prekindergarten year--in which the intervention was delivered--through first grade. This study was designed to explore the following research questions: (1) What are the immediate and long-term effects of the intervention on children's math skills?; (2) How much variation was there in effects across sites?; (3) Were curricular effects different for different subgroups of children?; and (4) What are the effects of the math environment and the fidelity of implementation on children's immediate and long term math gains, overall and across sites? [This research was conducted in partnership with Doug Clements and Julie Sarama at the University at Buffalo SUNY (recently moved to the University of Colorado).]