This chapter reports on the design, implementation, and testing of a new tablet-based tool designed to help upper elementary students develop a strong understanding of division. The tool provides an interactive visual model for the process of division and leverages students’ understanding of the array as a model for multiplication. Classroom observations, preliminary analysis of student work, and feedback from both students and teachers in a 4th grade classroom indicate that the tool has helped students increase their understanding of division and multiplication. The paper presents examples of student work that support this finding.