ABSTRACT
This chapter reviews theoretical and empirical work on children's understanding of numerical magnitudes, which laid the groundwork for our collaborative research. It discusses evidence from sociocultural perspectives that demonstrates how children's social world plays a critical role in their math development, especially in the years prior to starting formal schooling. The chapter demonstrates how integrating a cognitive development theory with sociocultural theories can inform the design of interventions and games for improving children's mathematical skills. It presents research that has extended the work in ways that further demonstrate the importance of examining children's social interactions and play to understand the substantial impact they can have on children's mathematical development both in the classroom and at home. Numerical magnitude knowledge provides the foundation for children's mathematical achievement. Overall, Bob's legacy will not only impact cognitive development, but also more broadly the intersection of children's social and cognitive development, which will help further deepen our understanding of children's learning.
