The purpose of this study is to investigate the effect of mathematical modelling activities on students' computational thinking (CT) self-efficacy in high school preparatory classes. In today's educational systems, computational thinking skills are of great importance to provide students with problem solving, analytical and algorithmic thinking skills. In this context, mathematical modelling activities stand out as an effective method to develop these skills in students. In the study, using a quasi-experimental design, data were collected using the BID self-efficacy scale before and after the application and the students' development in this process was analyzed. Mathematical modelling activities were applied for a period to the high school preparatory class students who formed the research group, and the change in the students' CT self-efficacy in this process was evaluated. The results showed that the modelling activities led to a significant increase in students' CT self-efficacy. It was found that students felt more competent in sub-dimensions such as problem solving, analytical thinking and algorithmic thinking. These findings suggest that mathematical modelling activities are a powerful tool for developing computational thinking skills. In conclusion, this study suggests that mathematical modelling activities should be more widely incorporated into the high school curriculum to develop computational thinking skills and draws attention to the importance of professional support for teachers in this process. It is suggested that future research should examine how such activities perform across different demographic groups and educational levels to obtain more generalizable findings.

Computational thinking skills, mathematical modeling, self-efficacy.