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US 3,935,649 AGranted
Multi-purpose mathematical aid
OwnerJames Richard Harteinventor
Life of this patent
Estimating the term…
Abstract
A multi-purpose mathematical aid designed to allow students, especially children, to see mathematical relationships by manipulation of materials. In its preferred form the mathematical aid comprises two moulded plates forming two halves of a storage case. Each plate has recessed square areas on one face for use with counting bars and catchment areas on the other face for use with disc or fractions of discs. The counting bars may, for example, be square or rectangular and may be adapted to rest in the recessed square areas.
Claims6
A mathematical aid comprising:
- a counting member having an upper face provided with a pattern of ridges having sloping sides and dividing the face into an arrangement of n .times. n recessed areas representing an orderly series of numbers;
- and
- a plurality of solid, relatively thin, multiple segment counting bars which may be positioned on said member to portray mathematical relationships, each bar comprising a plurality of joined segments defining units that collectively represent a number,
- each of said bars presenting opposed, upper and lower major surfaces, said lower surface having channel-like recesses therein provided with sloping sides for complementally receiving said ridges on the member to nest each unit of the bar in any one of the areas of said member, whereby to retain the units in place and provide selfcentering and self-alignment of the units of each bar with respect to the corresponding selected areas of said member,
- said upper surface of each bar having ridges thereon provided with sloping sides complementally receivable in the channel-like recesses in the other of said bars upon stacking thereof to center and align the units of the stacked bars.
2 more elements
Dependencies are inferred from the claim text.