Abstract
The 5E, an exploratory instructional model with growing popularity in current learner-centered educational practices, aims to develop learners' competencies. The study aims to evaluate the effectiveness of teaching fractions using the 5E instructional model to develop students' mathematical communication competency (MCC). The researchers used mixed methods with data triangulation in a 38-student experiment group (EG) who learned with the 5E model and a 41-student control group (CG) using traditional learning approaches to clarify the impact of the 5E model on the development of MCC, academic performance and learning attitude among learners. The research instruments include a pre-test, post-test, classroom observation, and a student survey. Subsequently, the data collected were analyzed qualitatively and quantitatively using IBM SPSS Statistics (Version 26) predictive analytics software. The independent t-test on the post-test scores of the two groups revealed that the academic performance of EG after the intervention was significantly better than that of CG with the significance level α = 0.05 and degree of freedom df = 77, yielding the p-value (Sig. 2-tailed) = 0.001. Meanwhile, given the significance level α = 0.05, the p-value (Sig. 2-tailed) = 0.001 and the Pearson correlation coefficient (r = 0.943), the result of the paired sample t-test implies that the mean post-test score of students in EG was significantly higher than that of their pre-test. Furthermore, with an effect size of approximately 0.88, these figures suggest that applying the 5E model in the experimental process positively affected the academic performance of the students in EG and the development of MCC. A qualitative analysis using classroom observations and student surveys revealed that the 5E model helped students in the EG develop their MCC and an increasingly positive attitude toward learning. In addition to these findings, it also reveals some limitations of the study and proposes recommendations for future research.