An examination of mental computations subject in the 1-5th grade mathematics textbooks and teachers' opinions

The aim of this research was to investigate how the subject of mental computations is handled in mathematics textbooks and to get primary and middle school mathematics teachers' opinions about teaching mental computation subjects and how it was handled in mathematics textbooks. This study, in which qualitative research methods were used, consists of two stages. In the first stage, the literature was examined and the criteria that should be found in the textbooks in the treatment of mental computation were determined by the researcher and the textbook was examined according to these criteria. In the 2021- 2022 academic year, the sections related to mental computation were determined and examined in a total of 11 mathematics textbooks belonging to primary school 1,2,3,4 and middle school 5th grades. In the second stage, one-to-one interviews were conducted with 5 primary school and 4 middle school mathematics teachers. According to the results obtained from the examinations of the textbooks, it has been observed that there were significant differences in the treatment of mental computation in the 1,2,3, 4 and 5th -grade mathematics textbooks in the textbooks of different publishers. In the textbooks published at the same grade level, it has been observed that there are differences in the number of studies on the mental computation outcome and the method used in the teaching of the outcome. At the same time, while the criteria that should be found in the processing of mental computation are taken into consideration in some textbooks, it has been observed that studies by the criteria sought are not included in some textbooks. According to the findings obtained from the teacher interviews, it was seen that both primary school and middle school mathematics teachers found teaching the subject of mental computation useful in terms of providing practicality in school lessons and daily life skills. However, the teachers stated that the subject of mental computation was a subject that is difficult both in teaching and learning, and that one of the biggest reasons for this was the individual differences of the students. There were different opinions among teachers about which grade level mental computation should begin. While primary school teachers argue that this subject should start at the 2nd -grade level at the earliest, most of the middle school mathematics teachers stated that this subject should be taught with the teaching of numbers and operations achievement, that is, starting from the 1st grade. In the opinion of most of the primary and middle school mathematics teachers, mental computation in the textbooks is partially sufficient or not sufficient. Keywords: Mathematics, Textbook, Mental Computations, Teacher.