Online education in the Covid-19 process and its application in mathematics lessons have caused a decrease in teaching quality. There are other determining factors of teaching quality; however, in this process, online education has been an important factor in the decrease in teaching quality. In order to determine how valid it is, the students we studied on, were given a questionnaire in accordance with the Likert scale and the results were evaluated. According to the results we obtained, most of the students stated that the teaching quality decreased in the online education process.