In this scenario students need to design a slide consisting of a curved and straight part in a smooth way. The task is designed in a way that students can explore and understand better the meaning of the slope of a function. Rogier's research is related both to the design of the scenario and the implementation done in schools in the Netherlands. It shows different ways how students solved the problem. At the same time he discussed the research potential of the task, students' understanding of the obtained results and showed that Realistic Mathematics Education and Theory of Didactical Situations might work well together for design of innovative teaching scenarios. Research has been done in collaboration with other MERIA members: Kristijan Cafuta, Selena Praprotnik and Sanja Antoliš.