After a short survey of the main steps which lead to the birth of “Early Algebra” as a specific field of studies, we sketch the main features of our theoretical frame and our work to promote algebraic thinking in the students and to educate the teacher at putting into practice constructive paths of teaching of early algebra. We then present an excerpt of a didactical process, realized in a third-grade class, which is meaningful from the point of view of pupils’ productions and of the classroom culture induced by the teacher. We conclude with some considerations about the effectiveness of our methodology of work for the pupils’ learning and for the teachers’ professional development.