The current understanding of the electronic educational resource is analyzes in the article. The definition of an electronic educational resource is given in the National Standard. The properties of the electronic educational resources, such as interactivity, multimedia, modifiability, cross-platform, are identified. The effectiveness of the use of the electronic educational resources in the educational process depends, among other things, on the level of interactivity, which is determined by the forms of user interaction with content and grows from conditionally passive forms to active, then to activity-related and, finally, to research. The complexity of creating electronic educational resources increases with increasing interactivity. Today, there are many software tools for creating electronic educational resources that technologically ensure the development of the necessary components and properties of electronic educational resources, besides interactivity that characterized by active or actionable forms of user interaction with content with research elements. The work presents the electronic educational resources developed at the Psychological and Pedagogical Faculty of Smolensk State University, in the creation of which students took part. The tools for resources development was the Mathematica environment.