This study examined the effects of training involving spatial versus nonspatial representations of numerical magnitude for promoting arithmetic fluency. The key goal was to advance theoretical understanding of the relation between spatial and math learning, while simultaneously laying the groundwork for the development of future educational interventions. Toward this goal, the study tested the hypothesis that the use of spatial representations during training facilitates arithmetic fluency via improvements in numerical magnitude knowledge. Participants (first graders from low-income racially/ethnically diverse backgrounds,