Jurnal Didaktik Matematika Dahiana, et al. ISSN 2355-4185(p), 2548-8546(e) DOI: 10.24815/jdm.v9i2.23479 248 Metacognitive Approach to Improve Students' Mathematical Problem Solving Skills based on Thinking Styles Wa Ode Dahiana 1* , Darma A. Ngilawajan 2 , Paul Arjanto 3 , Wa Halija 4 1,2 Mathematics Education Department, Universitas Pattimura, Indonesia 1 Mathematics Education Department, Universitas Pendidikan Indonesia, Indonesia 3 Guidance and Counseling Education Department, Universitas Pattimura, Indonesia 4 Ambon State Madrasah Aliyah School, Indonesia *Email: wdiana@upi.edu Received: 18 November 2021; Revised: 10 April 2022; Accepted: 31 October 2022 Abstract. Students' thinking styles are important factors for teachers to accommodate all types of students' thinking styles in a learning approach. Therefore, this study aims to determine students' mathematical problem-solving skills from their respective thinking styles using a metacognitive approach. The sample in this study was 60 students of class XII Madrasah Aliyah Negeri Ambon consisting of 31 Mathematics IPA-1 classes as the experimental class and 29 Mathematics IPA-2 classes as the control class. This research is a quasi-experimental study with a pretest-posttest control group design. The research instruments used were tests (pre-test and post-test) and the thinking style instrument. The data were tested by univariate test and t-test. The experimental class concluded; There are differences in the improvement of students' mathematical problem-solving abilities between groups of thinking styles and there is an influence of thinking styles on problem-solving abilities. While in the control class; There is no difference in increasing students' mathematical problem-solving skills between groups of thinking styles, nor is there any influence of thinking styles on problem-solving abilities. These results illustrate that students' mathematical problem-solving skills can be influenced by thinking styles as a result of the learning approach used, namely the metacognitive approach. Keywords: Thinking style, students' mathematical problem-solving skills, metacognitive approach Introduction Problem-solving skill is a common goal of mathematics teaching and is said to be the heart of mathematics. Problems in mathematics are non-routine questions where students do not immediately have a strategy or procedure to solve them but require the skills, understanding, and intuition to find the solutions (Smith, 2000). Problem-solving skills are critical for students to master, and it is one of the main tasks of teachers to help students solve various problems. However, teachers have not done this task well. Isyrofinnisak, Kusmayadi, and Fitriana (2020) revealed in their study that school teachers tended to use routine questions with routine problem- solving methods, without allowing students to think of solutions with their strategies or ways. This method causes students to experience great difficulties when facing more complicated mathematical problems, such as questions requiring problem-solving skills, contributing to their low academic achievement. The low mathematics achievement of Indonesian students is also shown by the Program for International Student Assessment (PISA), reporting that Indonesian students' achievement