NÚMEROS DECIMAIS NA SALA DE AULA: OS CONHECIMENTOS DE UM GRUPO DE PROFESSORES E A RELAÇÃO COM SUA PRÁTICA PEDAGÓGICA

The purpose of the present qualitative study involving seven teachers of a public municipal school in Campo Grande, Mato Grosso do Sul, in southwestern Brazil, was to investigate the knowledge held by 5th-grade teachers on decimal numbers and the relation between this knowledge and their teaching practice. Data were collected by observing Mathematics classes and by monitoring five activity sessions, with the participant teachers, about decimal numbers. Additional study data were gleaned from students’ notebooks, teachers’ lesson planners, and semi-structured interviews. The data were organized, according to the theoretical model developed by Lee Shulman for the knowledge base for teaching, into three areas: subject matter content knowledge, pedagogical content knowledge, and curricular knowledge. The results revealed gaps in the content knowledge on decimal numbers held by the teachers. This knowledge shortfall interferes with their pedagogical content knowledge and curricular knowledge, tending to influence the manner in which these teachers approach the process of teaching and learning of decimal numbers in the classroom. The findings also demonstrate the need to reassess the fundamental mathematical knowledge included in teacher training and refresher course curricula for practitioners in pre-school and early primary school settings.