flexible learning and the learning rechenuhr acting on clock, using the montessori perlenmaterials

摘要

learning and rechenuhr, consisting of multiple, flexible deployable elements to learn acting in cluster clock using the montessori perlenmaterials, characterizedon a base plate using a pen, a round plate centered with 12 uniformly arranged circular holes can be fixed; around a ring 12 is uniformly.circular holes arranged is placed in a ring around the 60 evenlycircular holes are arranged according to smaller; this is surrounded by two half rings.