The aim of this study is to examine the evaluations of teachers and pre-service elementary mathematics teachers on questions related to misconceptions commonly encountered in the field of numbers and operations learning. In the study, a special case study was conducted from qualitative research methods. The study included 18 secondary school mathematics teachers and 18 elementary mathematics teachers. Data were collected using an interview form developed by the researcher. The findings were analyzed by content analysis. The responses of pre-service teachers and teachers were tabulated with frequency and percentage information. According to the results of the study, it was determined that pre-service teachers focused on psychological reasons in determining misconceptions. In addition, it was determined that their solution suggestions for misconceptions were quite limited. Among the teachers whose responses were analyzed according to the length of seniority, it was determined that as the length of seniority increased, both evaluations were made from different perspectives in determining misconceptions and the solution suggestions offered diversified. From this point of view, it can be said that professional seniority in the teaching profession has a positive reflection on identifying the causes of misconceptions and producing solutions. It is thought that there is a need to deepen the field knowledge of prospective teachers.