Hypothetical learning trajectory for teaching straight-line equation

Difficulties in teaching and studying mathematics have become a huge issue nowadays. Mathematics subject in school is taught based on a procedural concept instead of its basic concept, particularly linear equations as known as a straight-line equation topic in Indonesian mathematics curricula. To foster students’ understanding of basic concepts in studying that topic, we need to develop a hypothetical learning trajectory. This study aims to describe the hypothetical learning trajectory for teaching the basic concept of slope, such as physical property, geometric ratio, and algebraic ratio. It is a part of design research in the first stage, namely preliminary design. The result may be a consideration for teachers teaching linear equations and to support students’ in studying slope conceptualizations.