Mathematical modelling is acknowledged to be one of the major dimensions of mathematical competence, and well-designed modelling activities can provide students with the opportunity to use mathematical concepts and procedures in a meaningful way. Additionally, modelling activities are regarded as suitable contexts for enabling students to use various problem-solving strategies and to synthesize their knowledge pertaining to different branches of mathematics. In this respect, computers have been regarded by mathematics educators as promising tools for designing modelling activities, and well-designed environments are viewed as increasing the benefits of modelling tasks. This study presents an example of the use of dynamic mathematics software in creating an interactive learning environment, first through a discussion of the pedagogical value of a real-world phenomenon selected for a modelling activity, followed by the implementation sequence of the activity in the classroom. The students' experiences during the implementation and their views about the activity are also discussed; and finally, recommendations about how to structure the implementation of modelling activities in the classroom are given.