This diploma thesis concentrates on the mathematical education in secondary schools during the 18th century. For this purpose, the development and the history of secondary schools will be explained. After the nationalisation of education, the secondary school was seen as an exclusive institution. During the time oft the enlightened Absolutism, the inclusion of the realities into the school curriculum was demanded. These important changes built the foundation of the mathematical education in secondary schools. In the following chapter the focus lies on the emphasis and the teaching content of mathematical education in the 18th century. Although many reform suggestions were made, the classical way was held in high regard. In this period of time the school book became a learning and teaching resource. The teaching tables developed by Philipp von Rottenberg were the foundation of the mathematical education of the children of Maria Theresia. The most important chapter is the analysis of the school book „Elementa Arithmeticae, Geometriae et Algebrae“, written in the year 1780. With the help of this book the teaching content of that time will be analysed and compared to todays contents. For this purpose, a comparision was made with the latest curriculum of the secondary schools as well with the teaching books used in these schools.