Math, blackboard and the trainers of mathematics' teachers: interpreting relations

The relation of teachers with the blackboard and the practical skills teachers developed in the educational process was and still is subject little discussed in the setting of educational research, because for a long time, the blackboard was synonymous of traditional and bank education and without any possibility of transformation didactic. The objective this work is to show important results on the subject, from the voices of some trainers of mathematics' teachers of Para, since the research identified in the constitution of trainers, personal and collective influences about particular knowledge to how use the blackboard as tool mediation in the educational space. At times and in different discourses, the blackboard was regarded as "auxiliary memory" of the construction of mathematical reasoning, and, for some trainers, mathematics is essentially visual. Thus, this article aims to contribute to theoretical discussions from the action in the classroom