Through Fernanda’s initial report, we realized that the activity started with an investigative question that enticed students. Who would make more money in the game: the one who chooses the green balls or the red ones? The way the problem was presented led the students to develop a hypothesis. They knew there were seven red balls, but also knew that the green color had a higher value. The teachers who planned this activity had predicted that this would happen. Once students didn’t know exactly what would be the answer, they had to negotiate. Then, the anxiety to know the answers and to not lose money led them to carefully observe the results of the game.