Abstract: A polyhedron with indicia carrying sections, for example a cube. The polyhedron is comprised of a first plurality of first larger sections, e.g. two halves of the cube, and the two larger sections are hinged together along neighboring edges. Their abutting, opposed surfaces, are hidden from view. When the larger sections are opened apart, this exposes indicia, e.g. a fraction, indicative of the portion of the whole polyhedron which each fractional larger sections comprises. Each of the larger sections of the polyhedron, e.g. a cube, are in turn openable apart around hinges to define smaller sections of the larger section. Surfaces of the hinged together smaller sections, which are hidden from view when the smaller sections are assembled, are exposed to view when the smaller sections are opened apart to define still smaller sections. Those indicia are related to the size of the smaller sections and, e.g., recite the fraction of the whole polyhedron which those smaller sections comprise.