The development of rbl-stem learning materials to improve students’ combinatorial thinking skill in solving local (a,d)-edge Antimagic coloring problems for Line Motif Batik Design

Combinatorial thinking is a problem-solving approach that involves analyzing and synthesizing different elements or possibilities to create new combinations or arrangements. It is a critical skill in various fields, including mathematics, computer science, biology, and optimization problems. Combinatorial thinking allows individuals to explore and understand the relationships between elements and discover novel solutions through systematic enumeration and manipulation. To develop students' combinatorial thinking skills, we need to support the learning process with learning materials of specific model and approach. In this study, we will develop RBL learning materials with a STEM approach to improve students' combinatorial thinking skills. We will use R&D (research and development) model for doing study of this research, namely Thiagarajan 4-D model. The developed learning materials met the criteria of being valid, effective and practical. The validity scores obtained for each material were 3.53 for RTM, 3.69 for LKM and 3.66 for THB. The observation results of learning implementation were 3.61 with a percentage of 90%, and the student responses were 3.75 with a percentage of 93.75 positive, so they met the practical criteria. Based on the test results, the researchers found that 82.75% of the students were complete so that they met the effective criteria.