Using the virtual-representational instructional sequence to support the acquisition and maintenance of mathematics for students with intellectual disability.

Mathematics instruction - and interventions to support mathematics teaching - for students with intellectual disability is important yet underexamined. This study explored a graduated instructional sequence referred to as the virtual-representational (VR) as a mathematical intervention. Researchers taught four students with disabilities what multiplication or division means and how to solve the problems first via virtual manipulatives and subsequently via pictorial representations. The researchers found a functional relation between student accuracy in solving multiplication or division problems and the intervention of the VR instructional sequence for three of the four students; for the fourth student, the researchers added the system of least prompts (SLP) to the virtual subphase of intervention. Researchers also found the students were able to maintain their accuracy in solving multiplication and division problems at rates exceeding baseline when instruction did not precede.