Examination of fifth grade mathematics textbooks in terms of number sense

The aim of the research is to determine the distribution of units for the use of number sense and number sense components according to learning areas in the fifth grade mathematics textbooks prepared according to the 2018 curriculum. For this purpose, three textbooks, one from National Education Publications and two from private publishing houses, distributed to students in the 2019-2020 and 2020-2021 academic years, were chosen as data sources. In order to examine whether the chapters in the textbooks are for number sense use, the analysis framework to be used in the study was decided in line with the classifications of the number sense components. The chapters in the books containing question statements were handled according to the use of number sense in their questions or solutions, and were examined in accordance with the determined framework. It has been determined that the number of analysis units for the use of number sense in the books is low. It has been observed that all the books have the most appropriate units for the decomposition and composition of numbers component. It has been determined that the number sense components used in the books differ according to the learning areas and the books. The results reveal that the units for the use of number sense are not sufficiently included in the textbooks. As a result of the discussion based on the research findings, suggestions were made for researchers and textbook authors.