Different didactic materials are used in teaching elementary mathematics to help students visualize abstract mathematical concepts. In order to bring abstract mathematical contents with larger numbers closer to the students in the third grade of primary school, it is recommended to use didactic materials that satisfy two principles: the principle of visualization and the principle of self-activity. With the principle of self-activity, students manipulate concrete didactic material in order to visualize mathematical contents, and at the same time visualize them, so the principle of visualization is emphasized. This paper describes the ways in which students adopt basic arithmetic concepts and lists and describes specific didactic materials and activities that can be used in the third grade in teaching mathematics. The following didactic materials are described: Cuisenaire sticks, Stern blocks, Unifix cubes and various Montessori materials. A research has been conducted in order to find out to what extent classroom teachers in the 3rd grade use specific didactic materials in teaching mathematics. 74 primary school teachers participated in the research. The results show that specific didactic materials are necessary for teaching mathematics to 3rd grade students and the didactic materials that primary school teachers use in their work with students are listed in the thesis.