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US 4,790,757 AGranted
Instrument for practicing multiplication
AssigneeKabushiki Kaisha Kawai Gakki Seisakusho
InventorFumitaka Takahashi
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AssigneeKabushiki Kaisha Kawai Gakki Seisakusho
InventorFumitaka Takahashi
Estimating the term…
An instrument for practicing multiplication to be used by children, in which there is a base plate, a printed plate fixed on the base plate, a group of horizontal cursors slidably installed on the base plate, a group of vertical cursors placed on top of the horizontal cursors and slidably installed on the base plate, and a top cover grass plate. These element are arranged as to calculate multiplication by sliding some of these two group of the cursors. One group of the cursors are given a sequence of numbers 1 to 9, and the other group of cursors are given the same sequence of numbers 1 to 9. When a number (X) of one group of cursors and a number (Y) of the other group of cursors are slided to one direction, a figure corresponding to the answer of X by Y and a group of marks equal to the answer are displayed on the instrument.
An instrument for practicing multiplication comprising a base plate, a square printed plate on the base plate and on which are printed vertical and horizontal rows of marks and figures, the rows of marks being interposed between the rows of figures, a set of elongate vertical cursors each provided with a vertical row of windows, the cursors being slidably installed side-by-side on said base plate and covering all but one of said vertical rows or marks and figures on the printed plate, a set of elongate horizontal cursors each provided with a horizontal row of windows, the horizontal cursols being slidably installed side-by-side on the base plate and covering all but one of said horizontal rows of marks and figures on the printed plate, the cursors being arranged for sliding a selected number (X) of said vertical cursors and a selected number (Y) of said horizontal cursors to a position toward one corner of the printed plate, and the windows, marks, and figures being mutually disposed whereby in said position of the cursors, a multiplication of the selected numbers X and Y is calculated, a figure representing the answer of the multiplication is displayed between respective cursors, and marks equal in number to the answer are displayed in aligned windows of the cursors.
An instrument for practicing multiplication comprising a base plate, a square printed plate on the base plate and on which are printed vertical and horizontal rows of figures interspersed with rows of blanks, a set of elongate vertical cursors slidably installed side-by-side on the base plate and covering all but one of said vertical rows of figures and blanks, a set of elongate horizontal cursors slidably installed side-by-side on the base plate and covering all but one of said horizontal rows of figures and blanks, the cursors in one of said sets being disposed under the cursors of another of said sets, the cursors in said one set each being provided with a lengthwise row or marks, the cursors in said another set each being provided with a lengthwise row of windows, the cursors being arranged for sliding a selected number (X) of said one set and a selected number (Y) of said another set to a position toward one corner of the printed plate, and the windows, marks, and figures being mutually disposed whereby in said position of the cursors, a multiplication of the selected numbers X and Y is calculated, a figure representing the answer of the multiplication is displayed between respective cursors, and marks on said one set of cursors, equal in number to the answer are displayed in aligned windows of the other set of cursors.
Dependencies are inferred from the claim text.