The investigation of thinking process of primary 6th ,7th and 8th grade students in the studies of composing and decomposing shapes in geometry and determination of their levels in this process.

This study has been designed to investigate deeply the processes in composing and decomposing shapes of the the primary 6,7 and 8th grade students who had different spatial thinking skills in and different Van Hiele geometric thinking levels. Moreover, the relation between the levels of composing shapes and different variables was studied.Within the scope of this investigation, both qualitative and quantitative methods were used. The case study was chosen as a qualitative method for investigating the process of composing and decomposing shapes and the survey was preferred as a quantitative method in order to investigate the relation between different variables and the levels of composing shapes.The participants of the case study consisted of total 38 students comprising 14 students from 8th, 13 students from 7th and 11 students from 6th grade. The data of case study in the investigation were collected by clinical interview. Mathematical questions and interview questions were used as a medium of collecting data in the interview. The qualitative data of the investigation consisted of the mathematical behaviors of students during mathematical questions, their answers to the interview questions and the observation notes of the investigator.The sample of the survey included total 1620 students. First 18 schools which were selected in the central of Izmir by using stratified sampling method , and then the students who were 510 of them 6th grade, 575 of them 7th grade and 535 of them 8th grade, were selected by using the random sampling method. Van Hiele Geometric Thinking Test? and ?The Skill Proficiency Test of Composing Shapes? were used as the quantitative data collection methodThe qualitative data of the investigation were analyzed by content analysis. As a result of the analysis the data, 10 levels were emerged in the field of composing shapes and to measure these 10 levels a scale was developed. The aim of developing this instrument was to discover the skill levels of students in a wider sample and to investigate the relevance (relation) of it with geometric thinking level, class and the variables of success.The quantitative data of the investigation were analyzed by using SPSS 15.0 statistics program. Frequency and percentage calculations as well as the analysis of variance and t test statistics were used. As a result, a statistical difference was found between the students? levels of composing shapes and their classes success, gender, mathematical success and geometric thinking levels.Key Words: Geometric Thinking, Spatial Thinking, Shape Composition, Shape Decompose