From 15th-19th November 2021, the third, next to last exchanging groups as part of the implementation of the project "Mathematics as a window to the world" of the Erasmus + program took place. This time the host school was Agrupamento de Escolas de Pedome from Portugal. Besides, Portuguese hosts and pupils of our school, students from other partner schools took part, such as "G. Pagoto" in Sicily and Escola Torre Barona in Spain . The visitors stayed in the UNESCO heritage-listed, picturesque town of Guimaraes, also known as the cradle of Portugal.