Lesley Wagner, elementary school teacher, Montgomery County, MD, has used CGI with her fifth-grade students for the past 15 years. She first became associated with the CGI research and development team in 1996 when she began her graduate work at the University of Wisconsin-Madison. She earned her PhD in math education under the direction of Thomas Carpenter, Co-Founder of CGI. Dr. Wagner is especially interested in helping teachers understand mathematical concepts through studying children’s intuitive problem-solving strategies. She is also interested in supporting elementary school students to develop an understanding algebraic thinking that will serve as a foundation for the math they will study in middle and high school. She has been teaching CGI Seminars since 2006.