| 主权项 |
1. A mathematics teaching aid comprising a plurality of elongated identical halves, said halves each comprising a right-angle trapezoid cross section with a non-parallel side disposed opposite said right-angle, said non-parallel side disposed at an acute angle relative to one leg of said right-angle, said halves reversed with respect to each other into pairs of said halves, each pair of said elongated trapezoidal halves flexibly joined together along a central line therebetween, said pairs of elongated trapezoidal halves arranged as a plurality of trapezoidal rows, said trapezoidal rows flexibly joined together at a juncture of adjacent vertexes of said acute angles of said right-angle trapezoid cross sections therebetween, said plurality of trapezoidal rows comprising a tabular unit having a width and length thereof, said tabular unit rigid in an horizontal direction and flexible in a vertical direction, each of said trapezoidal rows provided with numerals on at least one face thereof wherein each of said halves includes a portion of each of said numerals, wherein each said trapezoidal row is placeable adjacent any other said trapezoidal row by folding pairs of said elongated identical halves below a desired fractional set to place a numerator of a fraction above a denominator of a fraction thus presenting a plurality of equivalent fractional units to a learner manipulating said plurality of elongated trapezoidal halves, a first said trapezoidal row provided with consecutive cardinal numbers arranged upon an observed face thereof, successive said trapezoidal rows provided with different cardinal numbers arranged upon a observed face thereof proximate one end thereof wherein said first and said successive trapezoidal rows present multiples of said cardinal numbers in tabular form and equivalent fractions upon said observed face thereof. |
