This course is all about matrices, and concisely covers the linear algebra that an engineer should know. There are 38 short lecture videos, with a few problems to solve after each lecture. After each topic, there is a short practice quiz. Solutions to the problems and practice quizzes can be found in the lecture notes. At the end of each week, there is an assessed quiz. The mathematics in this course is presented at the level of an advanced high school student, but typically students should take this course after completing a university-level single variable calculus course. There are no derivatives or integrals in this course, but students are expected to have attained a sufficient level of mathematical maturity. Nevertheless, anyone who wants to learn the basics of matrix algebra is welcome to join.