This is a tutorial on teaching and programming in MATLAB. It is based on scripts and exercise in the course of numerical mathematics for students of the faculties Electrical Engineering and Information Technology and Computer Science and Automation after first term. This part I contains basic aspects and elements of numerical linear algebra, especially methods for systems of linear equations. Further parts give MATLAB-based algorithms and programming tools for eigenvalue problems, nonlinear equations and systems of equations, polynomial and spline interpolations and approximation.