Author: Maria Guida, Palmira Ronchi

Origin: ITALY

Implemented in: Belgium (Flemish Community), Spain and Hungary

The aim is for the students to learn about Eratosthenes’ Earth radius measurement and to make practical estimations of the error in measurement of physical quantities as well as to develop the capacity for abstraction. Students have to work with GeoGebra to draw ellipses using the gardener’s method. In order to get the feeling for it, the students can go into the garden to put a stick in the ground and observe the shadow and its length at different hours of the school day. It’s not meant to be a precise measurement but a device to promote discussion among students in order to train them in arguing scientifically. Back in the classroom, the teacher introduces Eratosthenes’ idea about the measurement of the Earth’s radius, which the students have to reproduce using GeoGebra. The students are asked to do online research and to calculate the difference between Eratosthenes’ measurement and the current value. This should encourage a discussion on what Eratosthenes’ imprecision was.

Success stories

This GP was praised for its combination of hands-on experiment with the use of ICT and GeoGebra. A Spanish teacher said that a mix of mathematics and a real experiment got him better results and more motivation of his students. Furthermore he said that this GP also helped him to introduce GeoGebra and ICT to his Maths classes. A Belgian teacher even said: “I persuaded other science colleagues and two students to do this real experiment during their trip to Rome. Students also started to work with GeoGebra to represent this problem. Since this experiment, some students have been viewing mathematics in unconventional ways, generating new ways of thinking, and they are engaged in problem solving, communicating, reasoning and representing these problems using geometric models in real life situations.”