Development of Outdoor Learning Mathematics Project Based Learning Tools on Simple and Compound Interest to Improve Students' Critical Thinking Ability

Abstract : This research is motivated by the continued dominance of conventional mathematics learning in vocational high schools, which rarely incorporates practical and contextual activities. Consequently, students’ critical thinking skills remain suboptimal, and learning tools based on the Outdoor Learning Mathematics Project (OLMP) are not yet available. This study aims to describe the process and results of developing OLMP-based learning tools for the topic of simple and compound interest that are valid, practical, and effective in improving vocational high school students’ critical thinking skills. This Research and Development (R&D) study adopted the 4D model (Define, Design, Develop, Disseminate). The subjects were 11th-grade students at SMKS 1 Pancasila Ambulu Jember. The developed tools included a Teaching Module, Student Worksheets (LKM), a FRISCO-oriented Critical Thinking Skills Test Package, and a User Manual. The results indicated that the learning tools met the validity criteria, with an average expert validity score (𝑉𝑎) ranging from 3.68 to 3.78 (valid category). The practicality criteria were also met, evidenced by an average learning implementation score of 3.78 (high category), a student activity rate of 91.35% (very active category), and a positive student response rate of 96.19%. Furthermore, the effectiveness criteria were achieved with a learning mastery rate of 85% (exceeding the 70% threshold), a moderate-to-high increase in the average N-Gain score, and an independent sample t-test showing a statistically significant difference compared to the control class (𝑝 < 0.05). Based on these findings, it is concluded that the OLMP-based learning tools for simple and compound interest are valid, practical, and effective in enhancing the critical thinking skills of vocational high school students.