Requirements to a digital educational resource are associated with the issue of thinking and speech in this paper. The author suggests a hypothesis of the need to take into account descriptive, generalizing, and regulating functions of speech when creating digital educational resource. Learning functions of the computer training program are compiled on the basis of the results of the observation of 7–9^th graders, who asked for help to cope with problems when mastering mathematics. The author describes the results of the study of perceiving and understanding the tasks by primary school children having difficulty with absorbing mathematics material, at the stage of testing author’s computer programs aimed at forming computing and arithmetic operations.