EFFECTIVENESS OF RMT-BASED LEARNING TRAJECTORIES TO SUPPORT RELATIONAL UNDERSTANDING

Straight line equations are one of the mathematical materials that are often difficult to understand. This difficulty is due to a teaching approach that often emphasizes memorizing formulas without a deep understanding, as well as a lack of reasoning and problem-solving exercises. As a result, students have difficulty building relational understanding, which is the ability to link different mathematical concepts and apply them in various contexts, so they are only able to do routine problems without understanding the essence of the material. This study aims to design a learning trajectory of straight line equations using the Rigorous Mathematical Thinking (RMT) approach and its effectiveness on students' relational understanding. The research method used is design research, which focuses on designing a learning trajectory and consists of three stages: preliminary analysis, experiment, and retrospective which are carried out in two cycles. The subjects of this study were 8th grade students of Palembang State Junior High School, with 32 students from grade 8.2 as participants in the pilot experiment and 36 students from grade 8.1 as participants in the teaching experiment, which were selected by purposive sampling. Data is collected through observation, written tests, and interviews. The data from the HLT design will be analyzed qualitatively and the results of the pre-test and post-test will be analyzed quantitatively. The results of this study produce a learning trajectory consisting of two main activities: 1) Solving problems related to line equations that go through two points, and 2) Solving problems related to perpendicular line equations. The learning trajectory developed is able to support students' relational understanding, where in the learning process, students are directed to utilize the various knowledge they have, determine the most effective and efficient strategies, provide detailed solutions, and believe in the truth of the answers they use in solving problems. In addition, pre and post test results, there is an increase in relational understanding by:, it can be concluded that the RMT-based learning trajectory is effective for improving students' relational understanding ofstudents in learning straight line equation material.Keywords: Learning Design, Relational Understanding, Rigorous Mathematical Thinking, Straight Line Equations