The description of student C’s answers to the three problems (question 1) referred to the figures: “he/she uses a good strategy and the figures are resolved correctly, observing the order”; it also referred to the fact that the student had no difficulties or hindrances and that he/she “generalizes in words.” On identifying the characteristics of the understanding (question 2), the PPT interpreted them similarly. Nevertheless, the PPT did not remark at all on the “functional relationship” or the “inverse process,” which are key elements that characterize this primary school student.