Abstract
Mathematical problem solving is an important skill for all students, including students with disabilities. This study was a systematic replication of a previous study that examined modified schema based instruction (MSBI) to teach problem solving of the mathematical domain of data analysis. Using modeling, graphic organizer, task analysis, and the system of least prompts (SLP), researchers taught middle school students with extensive mathematical needs (i.e., students taught in a special education mathematics class and performing below grade level in mathematical skills) to read a graph, interpret its scale, and solve a comparison addition problem. Researchers found a functional relation between the intervention package and student independence and accuracy across the three students. Students maintained their independence and accuracy two-to-three weeks after intervention ended.