A spread of COVID-19 has significantly influenced teaching methods at universities all over the world. In 2020, face-to-face lectures at our university were banned, or were allowed only with limited number of students. Thus, in an effort to keep high academic standards, teachers had to rely on synchronous and asynchronous forms of online learning. The paper analyze our experience with online learning of the subject Mathematics in Primary Education. We focus on several problems: an influence of a ban of face-to-face lessons to students’ ability to pass the final test, difference in level of knowledge of full-time and part-time students, correlation between an average study mean and results in a final test, impact of online learning on the satisfaction of students with their results, students’ preference of face-to-face lessons to online learning. The paper expands the results presented on the international conference XXXV DIDMATTECH 2022, published in the collection of abstracts.