The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 22, 1983
Filed:
May. 26, 1981
Applicant:
Inventor:
Donald R Williams, Los Angeles, CA (US);
Assignee:
Other;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G09B / ; G09B / ;
U.S. Cl.
CPC ...
434209 ; 434190 ; 40607 ; 108108 ;
Abstract
A three-dimensional device for teaching mathematical problems, comprising a stand having a number of open-ended shelves extending therefrom, the surfaces of said shelves being adapted to removably and interchangeably receive slides carrying different digits to set-up various mathematical problems, as conventionally done by paper and pen.