Actividades Investigativas con Números Irracionales en Clases con Principios del Lesson Study

The research focuses on identifying the contributions of Lesson Study (LS) to the conceptualization of irrational numbers among eighth-grade students aged between 13 and 15 years. The activity is carried out within a Semillero group, an extracurricular academic space in which research activities are conducted as part of the initial and ongoing training of mathematics teachers. The methodology adopts an interpretative approach, based on the analysis of experiences and meanings constructed by the participants. The results show that LS promotes collective reflection on lesson planning as well as negotiation and support in the design of investigative tasks that generate collaborative learning environments through argumentation and problem solving. These investigative tasks, being open-ended, non-directive, and challenging, change the dynamics of the mathematics classroom, fostering the learning of abstract concepts such as irrational numbers.