Abstract
At the beginning of the chapter, the desktop of the software, its toolbars, and main windows are introduced. Examples of interactive calculations with MATLAB® language are presented. Elementary functions, input and output commands, numbers and strings, vectors, matrices and arrays, flow control commands, relational and logical operators are discussed. Each command is presented in its most applicable form and with practical examples. At the end of each subsection, the commands studied are applied to elementary problems in the field of mechanical and tribological (M&T) sciences and technology, in particular to such as stress intensity factor, stiffness of a threaded bolt, adhesive force in contact between two spheres, and many others.