Background <p>The development of mathematical skills in students with intellectual disabilities can facilitate greater independence in everyday life. The ability to perform basic addition facts (BAFs) with fluency can facilitate the learning process of mathematics and the ability to perform quickly and correctly on a subject. This study examined the impact of simultaneous prompting with performance feedback (SP-PF) on fluency in BAFs.</p> Methods <p>Three high school students with mild intellectual disabilities participated in the study, which employed a multiple-probe, across-participants design.</p> Results <p>The results demonstrated that the SP-PF effectively enhanced the participants’ fluency in BAFs to the criterion level. All participants demonstrated maintenance of their fluency levels for at least 15 days following the instruction. On day 45, two students exhibited fluency levels that were very close to the criterion. Social validity data indicated that the participants were satisfied with the study procedures and their learning outcomes. Furthermore, social comparison demonstrated significant effects.</p> Conclusions <p>This study contributes to the literature on the effectiveness of the SP-PF intervention on fluency in BAFs in students with special needs. It shows that participants demonstrated the ability to answer facts without using their fingers.</p>