Why do pre-service teachers use the two-variable linear equation system concept to solve the proportion problem?

Abstract

Pre-service teachers need a good understanding of proportion concept so that later they can become teachers who can understand the concepts of mathematics to pre-service teachers. In this article discusses the mistakes of pre-service teachers when choosing the twovariable linear equation system concept to solve the proportion problem. This research is a qualitative research. Subjects in this study were two pre-service teachers of the fourth-semester mathematics education study program at one of the private universities in Yogyakarta. The research subjects were selected purposively with the following considerations: pre-service teachers who used the concept of a two-variable linear equation system to solve proportion and good communication skills so that researchers could explore the thinking process in determining problem-solving strategies. The findings of this study are that pre-service teachers experience interference in determining the knowledge that must be chosen to solve the problem of proportion.