Methodical instructions are designed to perform laboratory and practical work on the course "Informatics . Numerical methods of solving engineering problems on computers". and are aimed at students of construction and engineering specialties . The instructions give the conclusion of the main finite-difference relations used in the numerical solution of the Dirichlet problem for the Laplace equation and give a specific example of calculation, the corresponding graphs are constructed and the analysis of the obtained results is given. Based on the results of the manual account, an appropriate algorithm for solving this problem in the form of a flowchart and a program in the Turbo Pascal language has been developed. For independent work, students are offered tasks that are performed manually and on a computer, then the results are analyzed and compared