Abstract

Making decisions is a daily act in the human being, to greater uncer t aint y more diff icult it is to decide. From a lear ning situation, consisting of deciding between two random games with dices, the relationship between proportional thinking and probabilistic thinking is studied, considering three states for proportional thinking and three types of probabilistic thinking. Under the focus of an instrumental case study, the decisions and arguments of Chilean high school students are analyzed. The results indicate that there are both beneficial and harmful relationships between proportional and probabilistic thinking, and that the difficulties in determining probabilities are not necessarily due to the absence of the use of proportions. A teaching that considers argumentation and learning of the sample space is recommended to channel the use of intuitive resources.