Olly Steinthorsdottir, Associate Professor at the University of Northern Iowa, earned her Ph.D. in Mathematics Education under the direction of Elizabeth Fennema, Co-Founder of CGI. Prior to her PhD studies, she taught elementary and middle school mathematics for 10 years in her native country of Iceland. CGI has been the guiding force behind her math and math methods courses for pre-service teachers and in-service teachers for the past 20 years. Her research focuses on children’s mathematical thinking within the domain of rational numbers (fractions) and proportional reasoning. Dr. Steinthorsdottir is especially interested in gender equity in mathematics and is devoted to studying instructional practices that facilitates rich mathematical discourse and develops each and every child’s mathematical understanding. She is inspired by the creative teachers she has worked with. She has been teaching CGI Seminars since 2003.