Abstract
Abstract This paper is a part of a more significant study in design research aimed to create a learning trajectory in pre-algebra. The study was following the steps of the Preliminary Study, Teaching Implementation and Retrospective Analysis. In the current discussion, we will focus on the importance of visualization employed to represent the specific number pattern. The study was conducted in a state elementary school in Palembang with eight fifth grade students who participate during the Teaching Implementation phase. We gathered data from students’ written work, interviews, and observation during the lesson. The data were analyzed qualitatively using the constant comparative method. From the analysis, it was found that even though the problems were using the same number pattern, the students’ interpretation that leads to a correct generalization were highly influenced by the visual support. Hence, it is recommended to the future learning materials designers and teachers to consider the visual support matters to enhance the students’ mastery.