Math classes are primarily based on different types of exercises. Therefore, a development in teaching Maths is closely related to a development of the assignment-based philosophy. There was an essential change in the assignment-based philosophy, especially during the last few decades. This change was influenced by the introduction of the new final written exams in Austria. The purpose of this thesis is to show this development in the assignment-based philosophy by comparing different Math textbooks. For this analysis textbooks from 10th grade from the years of 1979, 2012 and 2015 were chosen. The analysis focuses only on examples from the chapters on exponential, logarithmic and trigonometric functions. The criteria for analysing include authenticity, openness and differentiability. Moreover, the exercises found in the according chapters will be divided into different categories of exercises according to a classification made by Regina Bruder and classified either as assignments for acquiring skills or as assignments for examining skills. By means of this analysis the tendency of the development of the assignment-based philosophy is to be assessed and if the trend from closed to open exercises can be confirmed.