Problem-solving is the most common activity of students. This thesis provides a short description of a mathematical task, its role in teaching, and the stages through which each task can be solved in a simple manner, without exception. For the purpose of this thesis, the word classification points to a systematic division of tasks in the teaching of mathematics. Many authors have tried to classify the tasks, therefore a difference can be found between standard and non-standard tasks, determination and demonstration tasks, numerical, textual and geometric tasks and size tasks. The goal was to find out how much the tasks, which were randomly chosen from the analysed mathematical textbooks, are focused on the students’ active learning of mathematics. To achieve this, Bloom’s taxonomy with its six levels of cognitive processes was used. The goals (outcomes) of learning are listed for each level, as well as the typical active verbs and the most common tasks from the mathematical textbook. Through the analysis of the tasks, according to the cognitive levels, it can be easily concluded that they are not completely synced with the contemporary teaching and that they do not cover all levels of cognitive processes. The textbooks mostly include the tasks relating to the factual knowledge which cover the lowest levels of cognitive processes, whilst the levels of synthesis and evaluation, which encourage the students to use higher thought processes, are left out.