The Development of RBL-STEM Learning Materials to Improve Students’ Combinatorial Thinking Skills in Solving Local (a,d)-edge Antimagic Coloring Problems for Line Motif Batik Design

Combinatorials require critical thinking procedures and convincing reasoning in the problem-solving process. Indicators of the combinatorial skills include identifying some cases, recognizing patterns from all cases, generalizing all cases, proving mathematically, and considering with other combinatorial problems. To apply higher-order thinking skills, we apply research-based learning with a STEM approach. To develop student combinatorials, educators must also equip the learning process with teaching materials. This research develops RBL learning materials with a STEM approach to improve students’ combinatorial skills. The teaching materials that developed have met the criteria of valid, effective, and practical. The validity scores that obtained on each device were 3.66 for RTM, 3.53 for MFI, and 3.69 for THB. The observation results of learning implementation were 3.79 with a percentage of 94.75%, and student responses were 97% positive so that they met practical criteria. Based on the test results, researchers found that 82.75% of students were complete so that they met the effective criteria.