Abstract
Presented research focuses on Content and Language Integrated Learning (CLIL). The aim of the presented research study was to plan, conduct and evaluate a two-month-long process of using CLIL in mathematics lessons at lower secondary school level.
In the teaching experiment, the impact of the connection of mathematics and English language on pupils' motivation and mathematics knowledge was explored. The experimental lessons focused on the topics of ratio, direct and inverse proportion.
The main method used in the experiment was action research. Other applied methods were quantitative methods (questionnaires) and qualitative methods (interview and mediated observation).
The experiment proved that the implementation did not have any negative impact on pupils' motivation, knowledge and activity in the lessons.