Özet:

This study aims at scrutinizing the middle school students' problem solving strategies with regard to the assumption component of mathematical thinking. The study is designed as a case study, among other quality research methods. The study group is comprised of 96 middle school students. The data in the study are obtained via non-routine problems prepared for the assumption component of mathematical thinking. When the strategies the students used in solving the problem are addressed, it is seen that they used the equating, with guess and verify strategies. In this regard, it is considered that the students used two of problem solving strategies and this issue should be paid attention in their education process in order for them to learn other problem solving strategies.