| 摘要 |
The invention relates to a device for the visual representation of proper fractions by means of circular segment areas. The invention is characterised by at least two disc-like elements which can be rotated relative to one another about a common centre and of which each extends, starting from a first edge line which runs radially from the centre to the circumferential rim of the element, about the centre in a prescribed direction, which is the same for both elements, over an angular range of more than 360 DEG up to a second edge line running from the centre to the circumferential rim in such a way that one surface side of each element on the second edge line respectively faces the other surface side of this element and each element thus itself overlaps with a subregion (overlap region) which exceeds the angular range of 360 DEG , and that the two elements are arranged to overlap and interlock in such a way that a first one of the two elements rests with its other surface side on one surface side of the second element and each element embraces the respective other element on both sides in its overlap region.
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