Improving Students’ Mathematical Representation through Contextual Teaching Materials with a Scientific Approach: An ADDIE-Based Development Study

Background: Mathematical representation is a fundamental competence that enables students to express mathematical ideas in multiple forms—verbal, symbolic, visual, and graphical. However, many junior high school students struggle to represent mathematical concepts effectively due to the lack of contextualized instructional materials and the limited application of active learning approaches in classrooms. Aims: This study aims to develop a valid, practical, and effective contextual teaching material based on the scientific approach to enhance students’ mathematical representation skills at the junior high school level. Methods: The research employed a Research and Development (R&D) design using the ADDIE model, encompassing five stages: Analysis, Design, Development, Implementation, and Evaluation. Validity was assessed by expert review, practicality through teacher and student responses, and effectiveness using a pre-test and post-test design to measure improvements in mathematical representation ability. Results: The developed teaching material achieved high validity scores from subject matter experts (3.71) and media experts (3.73). Practicality assessments revealed positive responses from both teachers and students, citing ease of use and contextual relevance. Effectiveness was demonstrated through a significant gain in students’ post-test scores, indicating improvement in verbal, symbolic, and visual representations. Conclusion: This study confirms that contextual teaching materials grounded in the scientific approach and developed through the ADDIE model can substantially enhance students’ mathematical representation skills. The learning process, which integrates observation, inquiry, experimentation, reasoning, and communication, encourages meaningful student engagement and deepens conceptual understanding. The contextual elements embedded in the material also bridge the gap between abstract mathematical theories and students’ everyday experiences. Therefore, the product of this research is not only empirically validated but also pedagogically powerful, and it is strongly recommended for broader implementation in mathematics instruction across junior high schools.