Enhancing Students' Competence in Decimal Operations Through the Design Thinking Approach: An Action Research Study

Decimal operations are essential for mathematical proficiency, yet students frequently struggle with conceptual understanding and procedural fluency. Existing research in mathematics education highlights persistent misconceptions in decimal placement and arithmetic due to interference from whole-number reasoning. These misconceptions hinder students’ ability to accurately perform decimal operations, particularly in multiplication and division. Despite various instructional interventions, there is a lack of structured, iterative approaches that actively engage students in concept-building. This study explores the effectiveness of a Design Thinking-based intervention, the DeThinkiMal Program, in enhancing students’ competence in decimal operations. This action research employed admixed-methods experimental design grounded in cognitive learning theories and constructivist mathematics education. The study followed the Design Thinking framework; Empathy, Define, Ideate, Prototype, and Test. Quantitative analysis included normality testing and paired t-tests using SPSS 29, while qualitative data from student interviews and daily feedback were analyzed through thematic analysis. Quantitative results showed a statistically significant improvement in decimal operations post-intervention, as demonstrated by paired t-tests (p = 0.001, Cohen’s d = 1.76). Qualitative findings revealed that students exhibited greater conceptual clarity, reduced reliance on rote memorization, and increased confidence in applying decimal concepts. By improving decimal comprehension through design thinking, this research supports Sustainable Development Goal 4, promoting quality education. It aligns with global educational goals advocating for inquiry-based, meta cognitive learning approaches.