Combinatorial thinking to solve the problems of combinatorics in selection type

Abstract

Helping students solve combinatorics problems is an essential effort to solve a problem. Formulating the stages of combinatorial thinking is one of the means to help students solve the problems of combinatorics in selection type. The research paper discusses combinatorial thinking stages. It aims to formulate and describe the combinatorial thinking stage to solve combinatorics problems in selection type. The study used a qualitative approach. Combinatorial thinking stages include (1) giving one combinatorial question in selection type, (2) observing by recording the subjects when they answered it, (3) formulating combinatorial thinking stages based on the video-recording results and answer sheets, (4) conducting a triangulation, and (5) making a conclusion of combinatorial thinking stages. The results of the research show that there are four combinatorial thinking stages, such as identifying, selecting, concluding, and reflecting. Identifying is when the students can identify a problem by writing all the information inside the test instruments. Selecting happen when the students can choose the object, and then structure it based on the criteria of the test instruments. Concluding means that they have made a conclusion based on the criteria of the problem inside the test instruments. Finally, reflecting means that they have checked the objects selected and structured them well using a combinatorics concept and procedure.