This study examines the impact of an online math learning program on third through fifth grade math achievement in Louisiana. Employing Zearn Math usage metrics and administrative data from the Louisiana Department of Education, the results indicate that grade levels that programmatically used Zearn Math scored, on average, about .03 standard deviation units higher on Louisiana's statewide math assessment. A placebo test using English-language arts scores and several robustness checks suggests that this may be an underestimate of the true effect. These findings come at a crucial time because pandemic-related school closures have led to a 20-fold increase in public school spending on Zearn-related materials between July 2019 and July 2021, and its presence continues to expand across the nation.