In teaching a variety of difficulties arise when working with functions. By the use of technology, functional thinking must not be limited to thinking in and with functions but it can be extended to a thinking in changes of objects. What is the influence of technology-based material to the individual conceptions of students of lower secondary school 1? Are dynamic worksheets able to support the development of skills? In this talk, specific dynamic GeoGebra-Applets, which are intended to support the development of appropriate skills, as well as the research design and first results of a corresponding qualitative study are presented.
