US3871114A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device for teaching the addition of fractions
Assignee: Individual
•
Filing: 1974-05-17
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Granted: 1975-03-18
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Expires: 1994-05-17
Abstract
Abstract A device for teaching addition and subtraction, respectively comprising a board having a longitudinal insert recess, a plurality of bars having the same width and a plurality of blocks, the blocks having a width exactly equal to integral numbers multiplied by the width of the bars. the bars and blocks are insertable in the insert recess and are complementary at least in part thereto such that the widths of the bars and blocks are aligned in the longitudinal direction of the insert recess. A slide rule is displaceably mounted on the board longitudinally with respect to the insert recess, and the board has a scale of fractional numbers corresponding to a division of the insert recess in the longitudinal direction thereof in units of the width of the bars. The slide rule is formed with an indicator cooperating with one of the fractional numbers for indicating thereby the answer to the solution of an addition or subtraction problem, corresponding to the blocks and bars positioned in the recess.
Inventors
- 👤 Joseph Honig
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 19:53
CPC Classifications
G; G09; G09B; G09B19/00; G09B19/02
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
178 words
A device for teaching addition and subtraction, respectively, comprising: a board having a longitudinal insert recess; a plurality of bars having the same width and a plurality of blocks, said blocks having a width exactly equal to integral numbers times the width of said bars; said bars and blocks being insertable in said insert recess and are complementary at least in part thereto in a manner such that the widths of said bars and blocks are aligned in the longitudinal direction of said insert recess; a slide rule displaceably mounted on said board longitudinally with respect to said insert recess; said board having at least one numerical fractional scale of fractional numbers corresponding to a division of said insert recess in said longitudinal direction of said insert recess in units of the width of said bars; and said slide rule being formed with indicator means cooperating with one of said fractional numbers for indicating the answer to the solution of an addition problem and subtraction problem, respectively, corresponding to the blocks and bars positioned in said insert recess.
Claim 2
Independent Claim
178 words
A device for teaching addition and subtraction, respectively, comprising: a board having a longitudinal insert recess; a plurality of bars having the same width and a plurality of blocks, said blocks having a width exactly equal to integral numbers times the width of said bars; said bars and blocks being insertable in said insert recess and are complementary at least in part thereto in a manner such that the widths of said bars and blocks are aligned in the longitudinal direction of said insert recess; a slide rule displaceably mounted on said board longitudinally with respect to said insert recess; said board having at least one numerical fractional scale of fractional numbers corresponding to a division of said insert recess in said longitudinal direction of said insert recess in units of the width of said bars; and said slide rule being formed with indicator means cooperating with one of said fractional numbers for indicating the answer to the solution of an addition problem and subtraction problem, respectively, corresponding to the blocks and bars positioned in said insert recess.
Claim 3
Dependent Claim
26 words
The device, as claimed in claim 1, further comprising a problem card set disposed on said board and containing a plurality of problems to be solved.
Claim 4
Dependent Claim
85 words
The device, as claimed in claim 1, wherein said board is formed with a guide slot longitudinally aligned relative to said recess, said slide rule is complementarily slidably disposed in said slot; and said slide rule is formed with at least one window constituting said indicator means, and said fractional numbers are disposed in said guide slot and said at least one window is aligned with said fractional numbers and is of a size to exhibit therethrough only one of said numbers at a time.
Claim 5
Dependent Claim
23 words
The device as claimed in claim 3, wherein said guide slot is dove-tail in cross-section; and said slide rule is trapezoidal in cross-section.
Claim 6
Dependent Claim
19 words
The device as claimed in claim 4 further comprising a handle on said slide rule for sliding the latter.
Claim 7
Dependent Claim
50 words
The device as claimed in claim 1, wherein said board includes a plurality of parallel scale marks extending longitudinally along said insert recess and uniformly dividing said recess in widths equal to that of said bars; and said scale marks aligned with corresponding fractional numbers of said numerical fractional scale.
Claim 8
Dependent Claim
21 words
The device as claimed in claim 1, wherein said blocks are scored in fractional widths equal to that of said bars.
Claim 9
Dependent Claim
45 words
The device as claimed in claim 7, wherein said blocks and bars are formed with depressed portions on an upper surface thereof, and said blocks and bars are scored on a lower surface thereof complementarily engaging in said depressed portions of said blocks and bars.
Claim 10
Dependent Claim
23 words
The device as claimed in claim 1, wherein said blocks and bars are coded and marked, respectively, to indicate their respective fractional widths.
Claim 11
Dependent Claim
18 words
The device as claimed in claim 1, wherein said bars, insert recess, and blocks are rectangular parallel epipeds.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-17 | 1978-09-16 | 1979-03-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-17 | 1982-09-16 | 1983-03-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-17 | 1986-09-16 | 1987-03-18 | $7700.00 | Window Closed / Lapsed |