Development of an Ethnomathematics-Based Student Worksheet (LKPD) Using The Bakar Batu Tradition on Three-Variable Linear Equation Systems To Support High School Students' Mathematical Conceptual Understanding

This study aimed to develop a student worksheet (LKPD) based on the ethnomathematics of the Bakar Batu tradition for three-variable linear equation systems (SPLTV) that meets validity, practicality, and effectiveness criteria within the research context. The study employed Research and Development using the 4-D model: define, design, develop, and disseminate. The product was developed in A4 print and digital formats. Participants were tenth-grade students at SMA Negeri 1 Dekai Yahukimo in the 2025/2026 academic year. Data were collected through expert validation, teacher and student response questionnaires, and a mathematical conceptual understanding test. Material validation reached 90.67%, media validation 94.00%, cultural validation 95.00%, and the combined score 92.73% (very valid). Practicality reached 93.33% based on teacher responses and 88.89% based on student responses (very practical). The effectiveness trial involving 20 students showed an N-gain of 0.605 (moderate). The LKPD uses Bakar Batu as a source of mathematical situations, scaffolds SPLTV modeling, and connects procedures with interpretation. The findings indicate that the LKPD is effective within the research context as an alternative SPLTV learning resource, while broader generalization requires larger samples and comparative designs.