One of the obstacles in learning mathematics is that students have difficulty solving math problems, especially word problems. This is one of the reasons why students make mistakes when solving math problems. The purpose of this article is to analyze the mistakes made by students when solving quadratic function word problems according to Kastolan's theory and find out the causative factors. Qualitative is this type of research. Class X MIPA 5 SMA N 1 Wiradesa as research subjects. Tests and interviews as data collection techniques. According to Kastolan's theory, three types of student errors are conceptual, procedural, and technical errors. Conceptual errors had the highest error of 26.26%, followed by procedural errors at 11.11 and technical errors at 2.02%. This error was caused by students not understanding the purpose of the questions so they used the wrong formula, students did not understand the concept of exponential functions so only half a step in answering the questions, they were not thorough and in a hurry, and students did not re-check the results of their answers.
Read full abstract