The multiplication of broken numbers: an educational experience on fractions inspired by Fibonacci’s Liber Abbaci

Abstract

This article describes a teaching experience carried out in a lower secondary school about the use of history in mathematics teaching. In particular, it describes the activities presented to 7th grade students regarding the multiplication of those that Leonardo Pisano Fibonacci calls broken numbers in the Liber Abbaci, and which are nothing but modern fractions. The activities presented are aimed at the autonomous understanding by the students of the rule of multiplication of fractions; to this purpose, laboratory activities were built that involve the use of various artifacts: the historical source, the vocabulary of broken numbers, fractional rods, and more.