CCT is implementing and evaluating Big Math for Little Kids, an early childhood mathematics curriculum designed to engage children ages four and five in learning key early learning mathematics concepts. CCT will implement the curriculum in Administration of Child Services child-care centers throughout New York City, working in collaboration with one of the curriculum's authors, Dr. Herb Ginsburg of Columbia University's Teachers College, as well as New York's Administration for Child Services. CCT will train teachers in the curriculum and conduct a two-year experiment to determine the curriculum's impact on early mathematics skills acquisition compared to the traditional curriculum. In the first year of the project, we refined the teacher training curriculum, developed our instruments, and conducted pilot research. In year two and three, we collected student and teachers data within 16 centers.