A child’s judgment about whether a figure’s boundary is open or closed develops visual discrimination. Activities like these serve as a prerequisite to further work with sets in mathematics, and to help children discriminate between certain letters, such as O and C.
There are two strategies to discriminate whether a figure’s boundary is closed or open. One asks the child to choose a starting point and follow the boundary around in one direction and try to arrive back at the original starting point. If the child is able to trace the figure and return to the starting place, the figure is termed closed. The second strategy involves determining whether you can move from the inside of the figure to the outside (or vice versa) without crossing any boundaries. If you can find a break or opening, the figure is called open.
Two sets with each one offering 12 cards for a total of 24 cards with real pictures isolated on a white background. Each card is printed on the back with an open or closed circle to signify if the figure is open or closed.
Printed on thick plastic, cut and all corners rounded.
|Whole Card||3¾ x 5 in.||9.5 x 12.7 cm.|
|Label Card||3¾ x 2 in||9.5 x 2.2 cm.|