1.4 Perspectives for Developing Mathematical Thinking
To know Katagiri’s theory, it is better to be familiar with the several perspectives for developing mathematical thinking which are well known in mathematics education researches. Many of the researches have been done based on their own research questions through case studies by observing limited children in the context of social science. Those researches are out of the scope of this book, because this book is aimed at explaining how to design classroom practice to develop mathematical thinking. To give a clear position to Katagiri’s theory, which has been used in the con text of classroom practice and lesson study for developing mathematical thinking, here we would like to present some bird’s-eye views of the theory.
1.4.1 Mathematical thinking: a major research topic of lesson study
In the National Course of Study in Japan, mathematical thinking has been continually enhanced since the 1956 edition. There have been several influences the development of the curriculum before and after World War II, such as the contribution of S. Shimada, who developed the textbook for mathematization in 1943, and the contribution of Y. Wada, [Ikeda, 2010; Matsuzaki, 2010; Mizoguchi, 2010]. Since the 1956 edition of the curriculum, mathematical thinking has been a major aim of mathematics education in the national curriculum.
Katagiri’s theory of mathematical thinking began in the 1960s and was mostly completed by the 1980s, and his lesson study groups have been using his ideas since 1960s, until today. If you are involved in research, you may feel that it is and old theory for your reference as it is necessary to refer to refer to the newest articles for research, but in the context of lesson study it serves as the theory that has been approved and used by a great number of teachers in the last half-century. Teachers consequently prefer this theory because of the many evidences that they experience in the process of developing children’s mathematical thinking in their classrooms. Many of these experiences are well explained by this theory. He has published 81books in Japanese for teachers to explain how to develop mathematical thinking. He is still writing. His theory was translated into Korean and he has been working with Korean teachers, too.
Until the 1970s, many math educators in Japan analyzed mathematical thinking for denotative ways of teaching it with specified content in the curriculum even if the national curriculum preferred the connotative ways of explanation. A number of types of the mathematical thinking were explained by many researchers. One of his contributions let to this movement and he composed it based on the importance of teaching and making it understandable to teachers even if they are not math majors. Another of his contributions was his ways of composition. In Part I, he composes them based on “mathematical attitude,” “ways of thinking.” and “ideas.” He explains that “mathematical attitude is the driving force of mathematical thinking because we aim to develop children who would like to think by themselves. This means that the child has his or her own wish to explore mathematics. Thus, developing the attitude of thinking ”