Methodology
With these different frameworks in mind (for each of the aspects that we would like to study),
we planned several didactical experiments, working inside normal classrooms with some of the
activities designed. For this, an elementary, middle economic class school (in the north of Mexico
City) was chosen and each of four research assistants selected a grade level, a topic and ten
activities from this topic to work with (“Car” chose second grade and Additive problems plus
Decimal system. “Let” chose third grade and Geometry. “Ili” chose forth grade and Fractions.
“Vic” chose fifth grade and Mental calculation and estimation.) These four assistants centered
their observations primarily on the “students’ cognitive advances” aspect of their particular topic.