Open and Closed ActivityEC0647L
EC0647 Open and Closed Activity. 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. A childs judgment about whether a figures 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.