Abstract
Ball as a spatial body and its boundary - sphere are terms that are well known by everyone and are percieved subconciously since early childhood. The exact meaning from mathematical point of view is specified by school mathematics.
Understanding of these terms enables the construction of knowledge about space, shape, sphere, ball. They help us to see shapes of atoms, molecules and other chemical structures more precisely.
The article will present ideas used by IBSE and project based education that improve mathematical knowledge about ball, sphere and spherical shapes.