Iwasaki & Steinbring (2009) identified the different types of "MATOME", which is one of the most important Japanese teaching concepts, in a mathematics class. They indicate that MATOME, especially in its traditional and classical form, which is a widely shared cultural expectation in Japan, would be a blind spot of Japanese mathematics teaching and suggest a possibility of the alternative version of MATOME: Student's MATOME. Confronting these difficulties as a reflective practitioner, it could be the starting point for Japanese teachers to have a better understanding about the mathematics class interaction where MATOME occurs. The research focus of this paper is to examine how students' MATOME / teacher's MATOME occur in mathematics class interaction, and to find out the causes behind the occurrences.
We conducted the school support project with some lesson studies in a third grade classroom with the class teacher Ms. M for improving mathematics classes over a four-month period from September to December, 2011. For the purpose mentioned above, two classes are taken from the third grade mathematics class in October and December, 2011.
We identified the situations where students' MATOME / teacher's MATOME occured in the two classes by analyzing the interaction from the view point of the different types of "MATOME". And then we examined features of the interaction where students' MATOME / teacher's MATOME occurred by comparing them, and further considered the causes. The results are summarized as follows.
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