Improving the Ability of Prospective Teachers: Errors Analysis of Material Geometry and Prevention Strategies

Abstract

This study analyzes the errors made by students when studying geometry and provides prevention strategies for prospective mathematics teachers. The method used in this study is a qualitative descriptive method. The instruments used were tests and interviews involving 16 prospective mathematics teacher respondents. Data were validated using the triangulation techniques by comparing answers based on test and interview results. The results of the research show the following conceptual errors made by the students: (i) while studying the concept of scale, it was seen that the writing of the scale can be expressed in the form of a fraction – the strategy to increase teacher’s TPACK ability is to ask students to analyze the difference between ½ and 1:2; (ii) errors in understanding the concept of a circle – the strategy to prevent this is to show a sample of a circular shape to the students; (ii) errors in distinguishing between the concepts of a circle and round – the strategy to prevent this is to remind students of the lyrics of the song “My hat is round” or the shape of the snack “tofu is round” and ask them to compare it with a ball; and (iv) limited understanding of the principle of the size of a triangle, namely the square of the longest side is less than the sum of the squares of the other sides – the strategy to prevent this is to ask students to analyze the patterns of pairs of sides. The novelty of this study not only analyzes the possible mistakes made by prospective teachers and students in teaching and studying geometry, respectively, but also provides an overview of the solution steps that teachers can take if their students face difficulty in learning geometry. Keywords: TPACK, errors analyze, geometry