Like Fröbel, Maria Montessori highlighted the importance of using objects and actively engaging in exploring the environment. Montessori's method, based on the Didactic Materials, addressed the stimulation of every sense (Montessori, 1912), and the design principle behind each of the objects from the Didactic Materials set, was to raise children's interest and curiosity. 2.1. Digital Manipulatives Recent technological developments made it possible to embed computational technology in objects, creating a new interaction paradigm with digital technology. Digital manipulatives 1 (Resnick et al., 1998) also referred to as tangible interfaces-TUIs (Ishii & Ullmer, 1997; Ullmer & Ishii, 2001) or tangible systems provide a more natural interaction, stimulating sensory and whole body perception, giving users freedom of movements, while creating richer experiences. Research has shown that physical manipulation greatly improves comprehension (Glenberg, 2010; Glenberg et al., 2011), and that digital manipulatives have the potential to expand the range of concepts that children understand (