This study aims to determine the ability of students' mathematical understanding of mathematical problems regarding the multiplication of two matrices, using an inquiry model approach. This research was conducted in March s.d. April 2021 on the learning video of class X TKJ SMK HMPTI Banjar Agung students (can be seen at the link https://youtu.be/yztsl7WM8U). The type of research used is qualitative research, research was carried out on 9 students who were grouped into 3 groups. The research subject was 1 student, which was determined based on the category of student answers and the group of students who presented their answers in front of the class. the data collection method used was observation of the results of student work on the video. The analysis technique uses data reduction, data presentation, and verification or conclusions. The results showed that the students of class X TKJ SMK HMPTI Banjar Agung already had the ability to understand mathematically on the topic of solving mathematical problems regarding the material of multiplying two matrices. Because students already have a mechanical understanding, inductive understanding, rational understanding and intuitive understanding. However, it has not been thorough in writing the matrix form and the lack of problem solving steps.