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Polygons and Fraction CirclesAge: 4 & up Prerequisites: Fraction circle application, polygon application. Screen objects: Ten red outlines of fraction circles down left side of screen, with red radii drawn to indicate the sectors. First circle is undivided, second circle is divided into two equal halves, third circle is divided into three equal thirds, etc. At bottom of screen are eight outlines of polygons placed in random order. All of these outlines are colored blue to match the geometric insets. Presentation: (Individual or small group)
Variations: Matching fraction circles and polygons side by side. Extensions: Design work with fraction circles and polygons. Points of Interest: Purple points appear when match is made. Highlighted points are sticky buttons which child may count. There are no onesided or twosided polygons. Control of Error: System responds by highlighting points where inscribed polygon and radii of fraction circle touch the circle. If a match is not made, no highlighting occurs. Direct Aims: To relate fraction circles and polygons by means of points on circle touched by inscribed polygon and radii of fraction circles. Indirect Aims: Preparation for exercises in recognition of external angles of regular polygons. Software Affordance: Easy to manipulate, transparent figures and control of error to support the child's autonomy. Software Constraints: Unlike the polygons in the geometric cabinet, the polygons cannot be rotated. Unlike the polygons made of geometry sticks, the sides of the polygons are rigid and cannot be added or removed. The sectors of the fraction circles cannot be removed from the circles. The sectors and circles cannot be rotated. 