On Improving the Students’ Combinatorial Thinking Skill in Solving Rainbow Antimagic Colouring Problem on Cryptography for E-Commerce Security Systems under the Implementation of Research-Based Learning with STEM Approach

Combinatorial thinking is the process of obtaining multiple solutions for discrete problem-solving. Combinatorial thinking skills have several indicators: identifying several cases, recognizing patterns from all cases, generalizing all cases, proving mathematically, and considering other combinatorial problems. The learning approach in schools is growing along with the development of science and technology, one of the approaches used in STEM. STEM education focuses students on solving problems in everyday life with the help of science, technology, engineering, and mathematics. This paper aimed to analyze the students’ combinatorial thinking skills after using a research-based learning worksheet with a STEM approach to solving the rainbow antimagic colouring problem. This study uses a mixed-method where this research combines qualitative and quantitative methods. The subjects of this research are undergraduate students of Mathematics Education, University of Jember. This study involved two classes, namely the experimental and control classes, where the researcher gave the two classes different treatments. The t-test compares students’ combinatorial thinking skills between the experiment and control classes after using research-based learning tools with a STEM approach for solving the rainbow antimagic problem. The homogeneity test results on the pre-test items indicated a significance value of .789 > .05, which indicates that the two classes are homogenous. The independent sample t-test score is .020 < .05, which means the difference is significant. It concludes that implementation of the research-based learning materials with a STEM approach can improve the students’ combinatorial thinking skills in solving the rainbow antimagic colouring.