This paper presents results of a research study focusing on the analysis, comparison, and description of students' attitudes towards the teaching of mathematics lessons presented in a foreign language (English) using the Content and Language Integrated Learning (CLIL) method in three elementary schools. It also highlights the difference between the attitudes of the CLIL method learners and those of their student counterparts who experienced similar mathematics lessons but in their mother tongue (Czech). The aim of the research is to test the hypothesis that the teaching of mathematics in a foreign language by the CLIL method would be evaluated positively by participating students. The research also focused on the question of whether or not, or to what degree, the implementation of the foreign language (English) along with the use of an interactive tool, such as GeoGebra software in mathematics lessons, was perceived as being meaningful and as significantly improving the effectiveness of student learning.