Patent ID: 9070297
Filing Date: 2015-06-30
Classification: G09B

Abstract:
1. A circular mathematical calculation device, comprising: an outer wheel, an inner wheel, and at least one selector all rotatable around a center point; said outer wheel comprising first and second outer sets of sequential integers extended circumferentially around said outer wheel, wherein said first outer set of sequential integers increases in a first direction, and said second outer set of sequential integers increases in a second direction, opposite to said first direction; said inner wheel comprising first and second inner sets of sequential integers, a lowest number of said second inner set is incremented by one over a highest number of said first inner set, said first and second inner sets increasing sequentially in the same direction; said at least one selector is configured to allow selection of a single digit of either said first or second outer set of sequential integers, while blocking from view a digit of a non-selected outer set of sequential integers, said selected single digit to be combined with a second digit of the same one of said first or second outer sets to form a mathematical problem, and said inner wheel is configured to be rotated relative to said outer wheel such that a known solution to said formed mathematical problem is aligned with said at least one selector, and thereby to provide multiple additional correct mathematical equations in additional locations aligned around said inner and outer wheels.