Angela Andrews has spent more than 25 years teaching preschool and kindergarten. In 1990, she received the Presidential Award for Excellence in Mathematics Teaching. She was a member of the preK-2 writing team for NCTM's Principles and Standards for School Mathematics (2000). Angela currently teaches mathematics at Scott Elementary School in Naperville, Illinois.

Paul Trafton was a professor in the mathematics department and Fellow in the Regent's Center for Early Developmental Education at the University of Northern Iowa. His long-term interest was in primary mathematics and led to his chairing the K-4 writing team of the Curriculum and Evaluation Standards for School Mathematics (NCTM, 1989).