This study aims to identify concrete teaching materials in secondary school mathematics textbooks. In the study, case study design, one of the qualitative research methods, was used. The documents of the study were selected among the secondary school mathematics textbooks, which were decided to be taught in secondary schools in the 2020-2021 academic year by the Ministry of National Education Board of Education, and are available at www.eba.gov.tr. The obtained data were analyzed using the descriptive analysis technique, one of the qualitative data analysis methods. Literature was used while creating the analysis framework. For the analysis of the concrete teaching materials in the secondary school mathematics textbooks, categories such as the type/name of the concrete teaching material, the grade level, the learning area, and the book section were determined. It was determined that the concrete teaching materials were mostly included in the 5th grade textbooks, followed by the 8th grade, 6th grade, and 7th grade textbooks, respectively. When examined according to the learning areas, the concrete teaching materials were mostly used in the "Geometry and Measurement" and "Numbers and Operations" learning areas, and the least in the "Probability" and "Data Processing" learning areas. Concrete teaching materials were mostly included in the activity and examples sections of the books. A total of twenty kinds of specially designed teaching materials were found in all the examined textbooks, and it was determined that all of them were used in accordance with the gains. It was determined that the most used specially designed teaching materials were algebra tiles, counting pieces, unit cubes, base ten blocks, fraction sets, feature cards, and hundreds chart, respectively. However, it has been determined that some of them are used quite frequently, and some are used very rarely.

Textbook, mathematics education, concrete teaching materials.