APOS theory is an instructional theory on how to learn the mathematical concepts studied; the application of APOS theory to the teaching of mathematics to help build students' understanding of various mathematical concepts. APOS theory creates a detailed structure consistent with learning mathematical concepts. APOS theory also assumes that mathematical knowledge results from the one-on-one construction of knowledge and helps students build a good academic spirit and understanding of mathematical ideas. The application of APOS theory to teaching mathematics helps to improve the ability to understand concepts, contributing to the formation and development of mathematical competencies for students. This study surveyed 43 high school teachers' general understanding and views on math competencies, problem-solving abilities, and APOS theory in teaching and learning the coordinate method in the plane in class 10; the research is carried out to serve as the basis for applying APOS theory to teaching the topic of coordinate method in the plane in class 10. Research results show that most teachers understand and see the importance of teaching in developing students' competencies (especially the ability to solve mathematical problems). However, most of the teachers in this survey barely knew the APOS theory