Using a Virtual Manipulative Intervention Package to Support Maintenance in Teaching Subtraction with Regrouping to Students with Developmental Disabilities.

To live independently, it is critical that students with disabilities maintain the basic mathematical skills they have acquired so they may apply these skills in daily life. To support maintenance of mathematical skills among students with developmental disabilities, the researchers used a multiple probe across participants design to examine the effectiveness of the VRA instructional sequence with fading support in teaching subtraction with regrouping to four students with developmental disabilities. A functional relation was found between the VRA instructional sequence with fading support and students' accuracy in solving the problems. Students also maintained the skill up to 6 weeks after the intervention.