Jennifer M. Bay-Williams, PhD, is a mathematics teacher educator at the University of Louisville, Kentucky. She has written many articles and books related to K-12 mathematics education, including the popular Elementary and Middle School Mathematics: Teaching Developmentally and the related three-book series, Teaching Student-Centered Mathematics. Bay-Williams is a national leader in mathematics education, having served as a member of the National Council of Teachers of Mathematics (NCTM) Board of Directors, secretary and president of the Association of Mathematics Teacher Educators (AMTE), lead writer for the Standards for Preparing Teachers of Mathematics (AMTE, 2017), and a member of the TODOS: Mathematics for ALL Board of Directors. Bay-Williams taught elementary, middle, and high school students in Missouri and in Peru. She currently works in elementary classrooms in the Louisville area, helping teachers and students attain basic fact fluency while also developing strong mathematical identities. Gina Kling is fortunate to serve the mathematics education community in a variety of ways. Since 2011, she has worked as a curriculum developer for the elementary mathematics curriculum Everyday Mathematics (based at the University of Chicago) with a focus on grades K-3. Recently she served as the grade 1 lead author for the Everyday Mathematics 4 State Editions, the author of the Everyday Mathematics 4 Quick Looks Activity Book, and one of the authors of Everyday Mathematics for Parents: What You Need to Know to Help Your Child Succeed. Kling has taught elementary mathematics content and methods courses for the past 15 years at Western Michigan University in Kalamazoo, Michigan, and is currently completing a doctoral degree in K-12 mathematics education at Western Michigan University.