Digital technologies have made their way not only into our everyday lives, but nowadays they are also commonly used in schools. Computers, tablets and smartphones are now part of the lives of this new generation of students, so it's only natural that they are used for educational purposes as well. Besides the interactive whiteboards, computers and laptops that are now widespread in schools, students with tablets, smartphones or graphic calculators are not an exceptional sight either. For mathematics teachers, it's important to know how and which of these digital technologies can be used during lessons. In this paper we would like to point out a few examples on how to use computers, tablets or graphic calculators effectively and their specifications for various topics, teaching methods and teaching forms. The results of the survey on using digital technologies by mathematics teachers in Slovakia are also presented.