The purpose of this study was to examine the effects of Incremental Rehearsal (IR) and traditional drill (TD) on retention of multiplication facts with 29 students in third and fourth grades with low mathematical skills. Results indicated that IR led to significantly more facts being retained, and was essentially equal to TD for efficiency as measured by number of facts retained per instructional minute. Memory scores accounted for 34% of the variance beyond mathematics calculation scores in retention of multiplication facts for the TD condition, but only 2% of the variance for the IR condition. Thus, retention of multiplication facts seems largely influenced by a student's memory skills when using less effective instructional techniques such as TD, while approaches like IR are likely effective regardless of memory skills. Impact and Implications: The current study found that Incremental Rehearsal (IR) was more effective than traditional drill (TD) in helping students retain multiplication facts, and the 2 interventions were equally efficient. However, retention of multiplication facts seems was largely influenced by the student's memory skills when using the less effective TD approach, and IR was effective regardless of memory skills. It may be more effective for practitioners to use an intervention that works despite memory difficulties than to base interventions on measures of memory for individual students.