Improving the efficiency of teaching mathematics by forming logical thinking on the examples of logical functions in Excel

Pedagogical technology consists of a certain system of methods and means of teaching. We suggest introducing logical and related mathematical functions Excel into educational technology of high school mathematics teaching. This will increase efficiency of students' developing fundamental knowledge of mathematics and related sciences, logical thinking and skills of building algorithms. Computer training tools can significantly increase the perception and assimilation of information in the learning process. The use of software products is of utmost importance for fundamental disciplines. Using them in parallel with the traditional methods of computing motivates to creatively approach the solution of practical problems, to search for an optimal option, to analyze the results. The paper describes the evolution of the branching implementation using a conditional operator, a history of its improvement from Assembler programming language to today's most commonly used Microsoft Excel program. The work describes the features and properties of Microsoft Excel functions that contain the conditional operator: IF, COUNTIF, SUMIF, COUNTIFS, SUMIFS, and describes the operation of the concatenation operator. IF function is used to show on examples the plotting charts of a piecewise continuous function. Other functions containing a conditional operator are used for the statistical task of determining the average salary of employees, depending on age. Given examples allow students to bridge the gap between the theory of mathematical logic and specific practical problems, which they have to deal with not only in the learning process, but also during the work on the main professions. This allows on the one hand to deepen understanding of the theory (as well as to identify problems, if any), and on the other hand, to provide students with useful practical skills and demonstrate a powerful mechanism of translation problem solving algorithm from «human» to «computer» language