MATHEMATICS ON LINE - Internet in the Secondary classroom - A theoreti cal and practical orientation for the didactic use of Internet, throug h Didactic Units and telematic experiences, with activities that atten d to the diversity with a focus on collaboration. It takes into accoun t the motivation and de-motivation of the student with regard to techn ology and offers wide information on on-line didactic materials for th e curricular development of the subject. It allows for combined work a mong different parts of Mathematics and with other curricular areas, t o favour a unified vision of knowledge. The file includes a CD.