Improvement of Mathematical Lateral Thinking Skills and Student Character through Challenge-Based Learning

the challenge relevance of lateral thinking and mathematical character that indicate geometry eternal issue is the most controversial mathematics branch, the difficult incomprehension source unit, at all levels of education. This research aims to improve the students’ ability of lateral thinking and mathematical characters through a challenged-based learning. This research is a Quasi-Experiment Non-equivalent Pretest-Posttest Control Group Design that involves 73 students of Mathematics Study at the Faculty of Tarbiyah and Teaching UIN Sunan Gunung Djati Bandung as the samples which is categorized into two classes, Class B as the control class, and Class C as the experiment class. The findings show that: the improvement of the challenge-based learning of students’ ability of mathematical lateral thinking is higher than the students that receive expository learning based on the students’ mathematics entirety and initial knowledge. There is an interaction effect between the learning types and mathematics initial knowledge toward the students’ lateral thinking. The challenge-based students’ characters improvement is higher than those who receive expository learning. The challenge-based learning can facilitate conflict processes, invention processes, social interaction processes and the students’ reflective processes so that the students’ lateral thinking and characters are better than the expository learning.