Vol. 7, Issue 10, Part F (2021)

Abstract
The learning process does not only emphasize aspects of remembering knowledge and understanding, but also aspects of application, analysis, evaluation and creativity. This is important because students can train thinking and problem solving as well as the application of concepts in everyday life. Therefore, a model is needed in learning, but in reality teachers are lacking in developing learning models that improve critical thinking and problem solving skills so that learning tends to focus on teacher. This has an impact on the achievement of student learning outcomes. This is evidenced by the number of 33 students only 9 students who succeeded and 24 students have not reached the minimum standard of learning criteria. It is necessary to apply learning that is able to create an active learning atmosphere for students, foster collaboration between students, and train thinking skills so that they can solve problems. The research objectives are to improve critical thinking skills through the use of Problem Based Learning Models, and to improve science learning outcomes for fourth grade students of SDN Inpres Walehunian Sagerat. The method used in this study is a classroom action research method and is designed in two cycles. The results of the study found that (1) through the application of a problem based learning model in science learning the material properties of light can improve critical thinking skills; (2) through the application of the problem based learning model, it can improve the science learning outcomes of students in the SD Inpres Sagerat class. Suggestions for fourth grade teachers can use problem based learning models in science learning, so that learning becomes more fun and meaningful and students are expected to always be active, creative, think critically, work together in groups and respect each other.