USE THEM AS EDUCATIONAL TOYS
[Tsunotsuno Dice] and [Tsunotsuno Tetra] are designed to represent three-dimensional dice with hardly any straight sections. They are mysterious objects, because when they are placed on a table, they appear to be cube-like, and when they are used as spinning tops, they appear to be almost spherical. We believe that it is important to encourage children to observe and touch objects in order to develop their stereognostic sense. They are excellent educational toys in this respect.
When the length of a side of a cube is 1, the length of a diagonal line on the surface is Root 2, and the length of the diagonal line of the cube (the protruding tip that acts as an axis when spun) is Root 3. They allow users to directly experience the mathematical measure of the differences between those lengths, which are out of sight in ordinary cubes. In this respect, they offer sufficient excitement to school-aged children as well as to adults. [Tsunotsuno Dice 1402226] and [Tsunotsuno Tetra 1567901] are patented (Registration of Designs).
SAFE AND SECURE
The pieces are made of polystyrene-based resin, a rubber-like resin material (elastomer). They have successfully passed the tests that evaluate the safety of toys (such as colorant elusion tests) in accordance with the Food Sanitation Act. Accordingly, they do not cause any harm, even when placed in babies’ mouths. They are designed so that the pieces are larger than the circular and oval assessment gauges used in the toy tests to prevent children from swallowing them by accident. They are safe educational toys that meet the Safety Toy Standards.