CCT implemented and evaluated Big Math for Little Kids, an early childhood mathematics curriculum designed to engage children ages 4 and 5 in learning key early learning mathematics concepts. CCT implemented 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 trained teachers in the curriculum and conducted 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.