Supporting Mathematical Skill Acquisition for Preschool Children with Autism Spectrum Disorder Using a Virtual–Representational–Abstract Intervention: A Single-Case Experimental Design

Some preschool children with autism spectrum disorder (ASD) experience difficulties acquiring foundational early numeracy skills, including single-digit addition. We evaluated the effectiveness of a virtual–representational–abstract (VRA) instructional sequence using a multiple-probe design across participants (single-case experimental design) to teach symbolic single-digit addition (e.g., 3 + 5 = __) with sums not exceeding 9. Three children with ASD attending a preschool setting in Türkiye (ages 4–7 years) participated. The instructional materials included 36 tasks (excluding addends that included 0). Results suggested improved accuracy in computing symbolic addition following the introduction of the VRA phases for each participant. Performance was maintained at 10 and 20 days after the intervention. Participants demonstrated person generalization when assessed by a different implementer, and teachers rated the procedures and outcomes favorably. Future research needs to examine VRA-based instruction for other foundational mathematics skills and with broader groups of children with disabilities.