Juanita Copley is a Professor at the University of Houston and currently serves as Chair of the Curriculum and Instruction Department in the College of Education. As the former program coordinator of Early Childhood in the College of Education, she directed the Early Childhood Mathematics Collaborative, a professional development project that involves beginning and practicing teachers. Her research involves the effectiveness of professional development models for early childhood teachers in mathematics. In addition, she researches young children’s understanding of mathematical concepts. Dr. Copley has written and edited three books about early childhood mathematics copublished by the National Association for the Education of the Young Child (NAEYC) and the National Council Teachers of Mathematics (NCTM). She has also authored several national mathematics programs. She wrote and directed the National Academy for Pre-K–2 teachers for NCTM and was the primary teacher for the Virtual Academy distributed internationally on the Internet. Using the train-the-trainer model, Dr. Copley has trained hundreds of early childhood leaders and indirectly or directly infl uenced the mathematics teaching/learning of early childhood teachers. She is an author for Scott Foresman - Addison Wesley enVisionMATH ©2009.