El conocimiento matemático que despliega y desarrolla un grupo de profesores en la resolución del problema del corral

: This paper focuses on the mathematical knowledge displayed and developed by a group of teachers when discussing a problem of maximization and some of its possible variations. The research was approached qualitatively by observing a group of mathematics teachers’ during the discussion involved in solving the problem. The analysis was carried out focusing on the teacher’s mathematical knowledge specificities, perceived in the Mathematics Teachers’ Specialized Knowledge (MTSK) perspective. The data reveal different in-depth levels of mathematical knowledge deployed and developed by teachers in problem-solving, which were associated with MTSK categories. The results show that, by solving the problem in different ways and observing different variants, the teacher’s mathematical knowledge was mobilized: in relation to the use of various geometric figures to design unusual pens; in the application and relationship of various mathematical notions in finding the resolution, and in the establishment of conjectures and possibilities of developing new knowledge. Thus, new indicators of teachers’ mathematical specialized knowledge are discussed.