Mathematics picture book on the number zero as a didactic tool in grade 1 of primary school

As one of the most important subjects, mathematics has a fundamental role in the development of key competencies that a student needs to develop a holistic personality. It is not just about mastering routine procedures, but also about the ability to solve problems, finding appropriate strategies, developing creativity, etc. (Žakelj et al., 2011). The child acquires the first experience with mathematics as early as the pre-school period (Kurikulum za vrtce, 1999); even more systematically, competencies begin to develop in the 1st grade of primary school, where lessons should be based on students' concrete experience and knowledge. Teachers can improve the students’ motivation and understanding by means of real examples, concrete illustrations, and various didactic aids (Žakelj et al., 2011). In the last two decades, picture books have become increasingly popular as a good didactic tool to enhance the students’ understanding of mathematical concepts (Hong, 1996; Haury, 2001; National Council of Teachers of Mathematics [NCTM], 2000). In our master's thesis, we write about a mathematical picture book, entitled ‘70 češenj,’ which was written as part of a project at the Faculty of Education, University of Ljubljana, but has not yet been tested in practice. We are interested in whether the mathematical picture book achieves its practical goals. The theoretical part consists of five chapters. In the first part, we present the teaching of the subject of mathematics and are focused mainly on the presentation of didactic aids. In the second part, we offer a presentation picture books in general, while in the third part, we aim our focus more specifically on the mathematical picture books. We describe their characteristics and define their usefulness in teaching. We have combined and summarized the main findings of various research studies in the field of the use of mathematical picture books for the purpose of learning mathematics. In the fourth part, we present a mathematical picture book, entitled ‘70 češenj,’ which is used in the empirical part and is the central subject of this paper. We describe the manner in which it was created, including both its content and the theoretical background. In the last part, we present the concept of the number zero, which is the theme of the mathematical picture book. We explain the history of its development, the way students understand the number zero, and list their misconceptions. We have summarized some of the findings of the most prominent research studies in this field. In the empirical part we investigate how the mathematical picture book ‘70 češenj’ as a didactic tool helps to understand the concept of the number zero in first graders, how they respond to mathematics lessons using the picture book, and how the picture book is received by the teachers of the first three years. We use a quantitative and qualitative research approach. Research results show that using the mathematical picture book ‘70 cherries’ improves the student's understanding of various aspects of the number zero. Students feel comfortable during lessons when mathematical picture book is included and do not have the feeling of learning (merely) mathematics, but other subjects also. Students likewise recognize its educational aspect. Our research also finds that teachers in the first three years recognize the mathematical picture book ‘70 češenj’ as a useful didactic tool in teaching mathematics and other subjects. They recognize the motivational and educational function of this didactic tool, and difficulties have been shown in recognizing the educational function. Teachers attach great importance to it, but there are also errors in understanding the mathematical content among them. Our research is important for rendering more recognizable of what is a relatively new but very useful didactic tool in Slovenia. It is expected to influence the use of mathematical picture books as a didactic tool in mathematics lessons. We believe that it would be necessary to acquaint both classroom teachers and students of this field with mathematical picture books and offer them guidelines for their use