Concrete–Pictorial–Abstract Approach in Developing Students' Understanding of Surface Area of Solids

Learning geometry, particularly the surface area of solids, is challenging for many Grade 8 students due to its abstract nature and reliance on spatial visualization. The Concrete–Pictorial–Abstract (CPA) approach, grounded in Bruner's theory of enactive, iconic, and symbolic representation, has been shown to enhance conceptual understanding in mathematics, yet its application in geometry remains limited. This study investigated the effectiveness of CPA in improving students' understanding of the surface area of solids. Using a single-group pre-experimental design, 30 Grade 8 students participated in a 4-week CPA intervention covering rectangular and triangular prisms and pyramids. A researcher-made 40-item achievement test measured conceptual and procedural knowledge before and after the intervention. Descriptive statistics and paired-sample t-tests were employed to analyze the data. Results indicated that students' mean pre-test score of 52.40 (SD = 8.12) increased to a post-test mean of 78.65 (SD = 6.54), with a statistically significant improvement, t(29) = 14.32, p < 0.05. These findings suggest that the CPA approach effectively scaffolds learning by guiding students from concrete manipulation to pictorial representation and abstract reasoning, reducing cognitive load and enhancing comprehension. The study concludes that CPA is a practical and evidence-based instructional framework that enhances conceptual understanding, procedural skills, and engagement in geometry, providing educators with a structured method to address persistent challenges in teaching the surface area of solids.