Angela Chan Turrou, PhD, is senior researcher and teacher educator at the University of California, Los Angeles (UCLA) Graduate School of Education and Information Studies. Her work lives at the intersection of children's mathematical thinking, classroom practice, and teacher learning. In her work with teachers and teacher educators across preschool and elementary settings, Angela leverages purposeful Instructional Activities driven by children's mathematical thinking to support teacher learning, collaboration, and generative growth. She is continually inspired by teachers who, on a daily basis, create space for children to drive the mathematical work and challenge the broader discourse of who does and does not get to be ?good at math.? Angela is coauthor of Young Children's Mathematics: Cognitively Guided Instruction in Early Childhood Education (Heinemann, 2017) and coeditor of Choral Counting and Counting Collections: Transforming the PreK?5 Math Classroom (Stenhouse, 2018). Angela lives in Los Angeles, CA. Find her on Twitter @Angelaturrou.

Nicholas C. Johnson, PhD, is assistant professor in the School of Teacher Education at San Diego State University (SDSU). His work investigates how classrooms shape children's opportunities to participate and learn. A former classroom teacher, instructional coach, and county office coordinator, Nick partners with new and practicing teachers to explore children's mathematical ideas and expand what ?counts? as math in school. He is a member of SDSU's Center for Research in Mathematics and Science Education, coauthor of Young Children's Mathematics: Cognitively Guided Instruction in Early Childhood Education (Heinemann, 2017), and a contributor (with Natali Gaxiola) to Choral Counting and Counting Collections: Transforming the PreK?5 Math Classroom (Stenhouse, 2018). Nick lives in San Diego, CA. Find him on Twitter @CarrythZero.

Megan L. Franke, PhD, is professor of education at UCLA. Dr. Franke's work focuses on understanding and supporting teacher learning for both preservice and in-service teachers. She is particularly interested in how teaching mathematics with attention to students' mathematical thinking (Cognitively Guided Instruction, or CGI) can challenge existing school structures and create opportunities for students who are often marginalized to mathematically thrive. Dr. Franke is a member of the Development and Research in Early Mathematics Education (DREME) Network at Stanford University where she is studying pre-K?2 coherence and designing resources for early childhood teacher educators. She lives in Santa Monica, CA. Find her on Twitter @meganlfranke.