In summer 2017, Long Beach Unified School District partnered with Khan Academy to support pilot teachers in their implementation of Khan Academy in the classroom. This study examined how the use of Khan Academy in the middle school mathematics classroom relates to student achievement on the mathematics portion of the state standardized assessment. Results indicated that students who used Khan Academy for more than 30 minutes a week, the recommended usage time, scored an additional 22 points (0.20 standard deviation units) on the 2018 mathematics portion of the Smarter Balanced Assessment, compared to students who did not use Khan Academy. Additionally, these results hold true regardless of race/ethnicity, gender, eligibility for free/reduced lunch, or English learner status.