ANALYSIS OF STUDENTS' MISTAKES IN SOLVING CONTEXTUAL MATHEMATICS PROBLEMS IN TRIGONOMETRY MATERIALS BASED ON CASTOLINE THEORY

Abstract

The purpose of this study is to describe the mistakes made by students in class X.7 in solving contextual mathematics problems of trigonometric material based on the stages of Kastolan, and to describe the factors that cause mistakes made by students of class X.7 in solving contextual mathematics problems of trigonometric material based on the stages of Kastolan. The method used is qualitative descriptive. The research was conducted at SMA Negeri 2 Slawi by taking research subjects using the cluster sampling method. The data analysis techniques used are data reduction, data presentation, and conclusion drawn. Data collection techniques are tests, interviews, and documentation. Based on the results of the study, it can be concluded that the mistakes made by students include: (a) Conceptual errors, inability to determine the appropriate trigonometric formula, not understanding the basic concepts of trigonometry, and connecting the solution with formulas that are actually not necessary, (b) Procedural errors, incompleteness in the completion step, not writing down the information known and questioned, unsystematic completion steps, and not writing down final conclusion, (c) Technical errors, errors in calculation operations, errors in determining trigonometric comparative values, and not conducting a review of the answers. Then the factors that cause mistakes made by students are: (a) Students do not understand the concept of trigonometry, (b) Students are not thorough in calculating, (c) Students are confused at certain stages and forget, (d) Students are in a hurry when working on the problem, (e) Students do not understand the purpose of the problem.