Students' mathematical critical thinking ability is one of the skills that need to be developed so that students can overcome future challenges. In addition, critical reasoning is one aspect of the Pancasila Student Profile that needs to be developed in the Independent Curriculum. In relation to efforts to improve these abilities, this study aims to determine the activities of educators and students in learning that applies the Problem-Based Learning (PBL) learning model with the Culturally Responsive Teaching (CRT) and Teaching at the Right Level (TaRL) approaches and to determine the increase in students' mathematical critical thinking abilities after carrying out the learning. The method used in this study is Classroom Action Research with two cycles, namely Cycle 1, consisting of 2 meetings, and Cycle 2, consisting of 3 meetings. The subjects of this study were students of class VIII A of SMP Negeri 13 Bandung. The conclusion obtained in this study is that the application of the PBL learning model with the CRT and TaRL approaches can improve junior high school students' mathematical critical thinking abilities.