This study examined the effects of a learning game, [The Math App] on the mathematics proficiency of middle school students. For the study, researchers recruited 306 students, Grades 6-8, from two schools in rural southwest Virginia. Over a nine-week period, [The Math App] was deployed as an intervention for investigation. Students were assigned to game intervention treatment, and paper-and-pencil control conditions. For the game intervention condition, students learned fractions concepts by playing [The Math App]. In the analysis, students' mathematical proficiency levels prior to the intervention were taken into account. Results indicate that students in the game intervention group showed higher mathematics proficiency than those in the paper-and-pencil group. Particularly, the significantly higher performances of intervention groups were noted among 7th graders and inclusion groups. The empirically derived results of the reported study could contribute to the field of educational video game research, which has not reached a consensus on the effects of games on students' mathematics performance in classroom settings.