Abacus
OwnerShlomo Friemaninventor
Life of this patent
Estimating the term…
Abstract
An abacus for assisting in teaching the place value, addition (including carrying), and subtraction, (including borrowing) comprises (a) a least 2 substantially parallel bars; (b) at least 18 beads mounted and independently moveable along the axis of each of the substantially parallel bars; and (c) means for maintaining each of the substantially parallel bars in a substantially fixed position with respect to each other. Preferably, the different groups of beads located on the various parallel bars are coded with some form of indicia (such as color) to denote their respective place in the 3-member sequence (i.e., ones, tens, and hundreds) of the base 10 numbering system.
Claims24
An abacus comprising:
- (a) a least 2 substantially parallel bars;
- (b) at least 18 beads mounted and independently moveable along the axis of each of the substantially parallel bars;
- and
- (c) means for maintaining each of the substantially parallel bars in a substantially fixed position with respect to each other.
5-6. (canceled)
8-9. (canceled)
11-14. (canceled)
17-20. (canceled)
An abacus comprising:
- (a) a frame;
- (b) from 2 through 9 bars with one end of each of the bars being affixed to one end of the frame, the other end of each of the bars being affixed to the opposing end of the frame, and with each of the affixed bars being substantially parallel to each other;
- and
- (c) 18 beads mounted and independently moveable along the axis of each of the affixed, substantially parallel bars.
An abacus consisting of:
- (a) a frame;
- (b) from 2 through 9 bars with one end of each of the bars being affixed to one end of the frame, the other end of each of the bars being affixed to the opposing end of the frame, and with each of the affixed bars being substantially parallel to each other;
- and
- (c) at least 18 beads mounted and independently moveable along the axis of each of the affixed, substantially parallel bars.
Dependencies are inferred from the claim text.