Ancient Zara game and teaching of Probability: an experimental research in Italian High School

This work is the beginning of a research activity on a first approach to probability from an informal point of view. We presented to students aged 17-18 a class activity based upon a simplified version of an ancient game named Zara. This game is famous in Italy because it is quoted by Dante Alighieri i n Purgatorio, VI, 1-3, and b y Galileo Galilei. It is interesting to u nderline that students adopt Laplace first and second principles without knowing them; according with Laplace ideas, several students made mistakes in non-symmetric probabilities. In this research the use of historical examples, combined with activity linked to everyday life, allows an effective approach to concepts of Probability.