The chapter consists of results of research aimed at primary school pupils and their problems in solving construction tasks in mathematics. The difficulties were identified via clinical interviews with pupils over solutions of selected diagnostic tasks.
The following problems were identified: pupils have problems with the distinction between the theoretical space and the space of representations (e.g., they do not work with a shape as a theoretical object but match it with its drawing); pupils tend to reason about prototypes of geometrical objects and thus attribute to the objects features which are not necessary or which are arbitrary (such as their placement or size); pupils make incorrect constructions, The difficulties are described and illustrated by pupils' solutions and extracts from the interviews. Their probable causes and re-education are outlined.
Our research results are connected to results of related international research, national testing and results of our online survey among elementary and lower secondary teachers.