The COVID-19 pandemic has significantly altered the organization and scheduling of high schools in Spain. Due to pandemic restrictions, most students from grades 9 to 11 come to class only on alternate days. In this situation, e-learning and distance learning have gained prominence as necessary methods of instruction. In this study 68 students from grades 9 and 10, attending on alternate days, participated in an online teaching experience for the first time in their lives. This took place during the first trimester of the 2020-2021 academic school year. On days when they did not attend class in person, students were expected to watch the mathematics classes which were broadcasted live via YouTube. Students could either watch the classes live and ask the teacher questions via an online chat, or alternatively, they could watch the pre-recorded classes at a later time. The two options were analyzed using quantitative and qualitative methods. Results showed a continuous decrease in the number of students who preferred the first option, switching progressively from online live classes to pre-recorded classes as the weeks passed. The qualitative results explained this progressive decrease as students preferred to watch the teacher's explanations several times. Although e-learning is absolutely necessary in the 21st century, and especially during the current pandemic, controlling students' level of application to distance work and online learning is still a challenge.