<![CDATA[Critical thinking is one of the most essential competencies in 21st century education that needs to be developed systematically throughout the learning process, and mathematics is one of the most strategic subjects for facilitating its development. However, in practice, students at Vocational High Schools (SMK) still demonstrate relatively low critical thinking skills, which is largely attributed to the dominance of teacher-centered learning approaches that provide little room for active student involvement in problem-solving activities. This condition reinforces the urgency of implementing a learning model capable of promoting greater student participation, one of which is Case-Based Learning. Based on this issue, the present study was designed to examine the extent to which Case-Based Learning influences the improvement of critical thinking skills among SMK students. A quasi-experimental method was selected as the research approach, adopting a pretest–posttest control group design as the methodological framework. Two classes served as the research sample, namely the experimental class that received instruction using the Case-Based Learning model and the control class that continued with conventional learning, each consisting of 30 students. The research instrument consisted of critical thinking essay tests administered to both groups before and after the intervention. Data analysis was carried out using the t-test after the assumptions of normality and homogeneity were satisfied. The results revealed a statistically significant difference in critical thinking skills between the two classes, with the experimental class recording a higher posttest average compared to the control class. These findings confirm the effectiveness of Case-Based Learning in supporting the development of students’ critical thinking skills, leading to the conclusion that this model serves as an effective and viable alternative in mathematics instruction at the vocational high school level.]]>
