Research on the Development of the Percentage Visual Estimation with Computer Models

The article describes a study on the development of the percentage visual estimation and presents the results of participants from different age groups. For the implementation of the study, computer models were used, created with the dynamic software GeoGebra and provided with free access in the Virtual Mathematics Laboratory, developed by the Institute of Mathematics and Informatics of the Bulgarian Academy of Sciences. To assess the effectiveness of the use, a pre-test and a post-test were used, separated in time by a short work with the specified computer models. The results of the preliminary self-assessment of the participants and their assessment at the end of the lesson regarding the usefulness of solving the tasks set were also reported.
Different options for the use of these educational resources are commented on, the possibilities for the simultaneous development of digital and mathematical competence when working with them, as well as the possibility of their use in STEM centers.