Welcome to HABA's Clever Up! Building System. Building blocks help children to fulfill two natural needs: imitating the grown-ups and constructing things. This is how children familiarize themselves with the adult world. Children use the building blocks to playfully shape the space around them and at the same time begin to grasp the concept of the third dimension. Through constant repetition and trial and error, they also acquire an empirical understanding of the laws of physics.