<b>Knowledge and School Practices of Teachers of Initial Years Refering to Decimal Numering System

Abstract

This paper presents the results of the research that investigated the professional knowledge and the pedagogical practices, of teachers of 2^nd and 3^rd years of Elementary School, referring to the Decimal Numbering System (hereby SND). The theoretical references, that guide the investigation and the data analysis, are based in the historical-cultural approach. The research configures itself as a qualitative case study. Two teachers of the 2^nd year and one of the 3^rd year participated of the investigation. The data source was questionnaires, field diary, observations, interviews and school documents. The data indicated that the teachers lived insufficient mathematical knowledge processes in the schooling and in the initial and continuing professional formation. There are evidences of fragilities in specific, pedagogical and curricular knowledge related to the SND and that, even though the teachers’ pedagogical work are different in some moments, their practices become similar when teaching the SND without considering its genesis and historicity and when they propose exercises that do not promote reflections about their rules and properties. Besides that, the absence of a consolidated proposal of collective pedagogical work and of a continuing formation in the school limits the possibilities of the teachers to expand their professional knowledge and to promote qualitative changes in the process of teaching and learning mathematics.