The study explores implementing a didactical design approach in elementary school students learning mathematical concepts such as factors and multiples. This research was conducted over four meetings at one of the elementary schools in Bantul Regency, Yogyakarta, Indonesia. The research subjects consisted of one class teacher and seventeen students. This research uses the qualitative method of the Didactical Design Research (DDR) model through four stages: didactic-epistemological analysis, didactical design, implementation, and institutionalization of scientific knowledge. Data was collected using interviews, observation, documentation, and focus group discussions (FGD) between teachers and researchers to improve the didactic design. It emphasizes the importance of teacher skills in creating learning activity plans, including designing pedagogical didactic anticipation for learning the concepts of factors and multiples. The results of the implementation of didactic design not only pave the way for minimizing intervention but are also oriented towards student involvement, student creativity and the teacher's role in institutionalizing the knowledge that students have constructed. The research highlights the effectiveness of this approach in helping students grasp abstract mathematical concepts, emphasizing its role in enhancing learning outcomes. It contributes significantly to mathematics education, especially in elementary settings, by demonstrating how well-designed didactic and didactic situations overcome learning obstacles and foster more profound understanding.