The primary goal of this project is to expand and generalize the literature base for interleaved practice. This study compares interleaved practice to repetitive practice and incremental rehearsal within the context of learning single digit math facts. Third grade (n = 34) and fourth grade (n = 40) students learned target single digit math facts in one of three practice schedules. Using a within-subjects counterbalanced and crossed design, students were exposed to three different learning conditions. Comparisons were made regarding accuracy of responses during acquisition trials and retention trials, as well as learning efficiency. Results indicated very few differences between practice conditions regarding acquisition accuracy, increased accuracy during retention trials for interleaved and incremental rehearsal practice, and higher learning efficiency for interleaved practice when compared to incremental rehearsal. Student pretest accuracy moderated effects of practice schedule and opportunities to practice resulting in different outcomes for students with different levels of mastery at the outset of the intervention. This study is the first comparison of interleaved and incremental rehearsal practice, and the results suggest that interleaved practice is the most efficient schedule for drilling math facts.