In my paper, I discuss the results of individual observations of pupils aged 13-14. These children undertook an attempt to solve problems which were designed in order to bring about an inductive type of generalizing. The main aim of the study was to classify typical methods of proceeding, which represent the pupils’ ways of reasoning and to determine what influence a particular method of proceeding may have on the final outcome of their work. These results indicate the general pupils’ strategies of generalizing. Presumably, visual thinking produces a positive effect on the pupils’ process of generalizing and abilities to describe regularity with the aid of a letter symbol.