Microeconomics studies the choices made by individuals under conditions of scarcity of resources and time and the interaction between different decision makers. Scarcity forces economic actors to choose one opportunity among many. Microeconomics with Spreadsheets starts with the mathematical preliminaries and covers consumer theory, producer theory, general equilibrium, game theory, market structure and economics of information.The reader will use numerical tools to analyse problems that cannot be analysed analytically. There is a natural synergy between rigorous proofs and numerical methods, since before using a numerical method one should also prove that a solution exists and analyse whether it is unique, and therefore be able to interpret properly the output of a program.