Abstract-Tablets, smartphones are becoming increasingly common and interfaces are predominantly tactile and often multi-touch. More and more schools are testing them with their pupils in the hope of bringing pedagogic benefits. With this new type of devices, new interactions become possible. A lot of studies have been done on the manipulation of 3D objects with 2D input devices but we are just at the beginning of studies that made a link between needs of pedagogy and possibilities of these new types of interactions. FINGERS© is an application for learning spatial geometry. It's written for pupils from 9 to 12 years old. Interactions have been designed with teachers. Some interactions are specifics for 3D geometry (3 DOF translations, rotations, nets, combinations of cubes, etc) and someone are general like designation or multi-selection. A lot of grammars of gesture propose a set of interactions to select an object or a group of objects. Multi-taps or lasso around an area are commonly adopted interactions. Performing geometry exercises needs imaging another interactions. For example how selecting all Cubes, how selecting all green objects. The real question is how introduce a parameter in selection. After presenting the limits of current solutions, this communication presents the solutions developed in FINGERS©. We explain how they allow a "parameterized" selection.