Susan Empson is a professor and the Richard Miller endowed chair of mathematics education at the University of Missouri. Her research has consistently been supported by the National Science Foundation and the Spencer Foundation, including a recent NSF grant to study elementary teachers' learning and development centered on teaching in ways that are responsive to children's mathematical thinking in the domain of rational numbers. Susan is a coauthor of bestselling books focused on Cognitively Guided Instruction (CGI), including Children's Mathematics and Extending Children's Mathematics. Read a blog post adapted from Extending Children's Mathematics: How to Build Meaning for Fractions with Word Problems