Education and demonstration – Mathematics – Arithmetic
Patent
1989-01-18
1989-12-05
Grieb, William H.
Education and demonstration
Mathematics
Arithmetic
434203, 434205, G09B 110, G09B 1902
Patent
active
048849731
ABSTRACT:
An aid for teaching children addition and subtraction of two numbers according to an algebraic equation. Cards bearing selected integers and one card bearing a plus or minus sign are placed by the teacher on a panel in horizontally aligned spaces corresponding to the terms of the equation but for one space. The student is then challenged to hang a card displaying the appropriate integer or sign in the vacant space. Rings slidable on a horizontal rod are positionable in the spaces in quantities corresponding to the integers thereat for visual reinforcement of the equation.
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