In this paper, we describe an idea for mathematics lectures that involves using digital tools for first-year university students. Materials in the Moodle course include live broadcasts, lecture recordings, Moodle tests, sample solutions and videos. The aim of the paper is to find out from students' feedback which digital tools help them understand the material better. We focus also on the tools used in the Desmos environment slides. Students' feedback showed that using Desmos slides during the lecture helped them understand the theory better and try the tasks immediately. Graphical Desmos tools were the most appreciated because they helped to visualize the studied topic.