The current study was conducted in Taiwan to examine the effectiveness of using a self-monitoring strategy to increase the percentage of completion of classroom tasks for three high school seniors with moderate intellectual disability. We used a multiple-probe-across-subjects single-case design to evaluate the use of a self-monitoring tool to increase task completion. The unique feature for this study is that learning characteristics of participants were considered while designing the self-monitoring strategy. The primary result of the study is that the self-monitoring strategy was effective. Participants used the self-monitoring tool more often when guided by visual prompts and rhymes, and their differential decision-making and reasoning behaviors increased their motivation for learning. We share implications for research and suggestions for teachers when applying the self-monitoring strategy.