Özet:

The purpose of the present study was to examine the Mathematical Content Knowledge (MCK) of Middle School Mathematics Teachers (MSMT) on prism concept. The purposive sampling strategy was used in the study with the design of case study. The participants were composed of six MSMT having different number of experienced years. The triangulation was made by using the techniques of semi-structured interviews, semi-structured observation and document analysis. In the data collection process, the interviews and observations were recorded by audio recordings and the lessons of three teachers were recorded by video camera. The data were analyzed by the techniques of qualitative data. In the analysis of data obtained, content and descriptive analysis techniques were used. The packet program of Nvivo 8 was used in the analysis of MCK. At the end of the study, it was determined that teachers often had difficulties about defining the concept of prism, to identify the key elements and the recognition of the different surface development of the cube.