Then the circle may be compared with the ball, and the children are asked: “What things are round like the ball?” “Orange, apple, etc.” “And what things are round like a circle?” “A penny, a shilling, etc.” “What has the circle that the ball has not?” “The circle has two flat faces, and the ball has only one round face.”
The Square is somewhat familiar to the child, who has noticed the shape of his books, and the table. It has four sides all the same length; this fact may be taught thus:
Take a long stick or ruler. Teacher says: “I will measure the sides of the square. Johnnie shall hold it for me” (measure the top edge, and cut off a piece of stick just the length). Show it to the children, and say: “This stick is just as long as the top edge of the square. I will give it to Mary to hold. Now we will measure the bottom edge” (again cut the length). “This is the length of it” (holding up the stick).
The right and left sides are measured in the same way, and the child now holds four sticks. Let the children count how many sticks there are, and notice also that all four measure exactly the same, and then they will see that the square has four sides all the same length. Then ask for objects of this shape.
The Oblong is measured in the same way as the square, and the sticks are cut the lengths of its sides. The children then see that the sticks cut to represent the sides of the oblong are not all of the same length, but that two are short, and two longer, so the oblong must have two long sides and two short sides. Let a child point to the two long sides, and another to the short ones.
Then the children are asked to name all the things they can see that are oblong in shape, such as the table, door, window. They may also name objects at home—dresser, piano, bed, and many other things.
The Oval is frequently taught after the circle, but as the difference between square and oblong is more marked than the difference between circle and oval, the former comparison if taken first may help the child to understand the latter.
Take a square and draw a circle on it, then take the oblong and draw an oval shape upon it. Ask the children, “How is this shape different from the round shape on the square?” “It is longer.” “Why?” “Because the oblong is longer.”
Now show the oval with the round or circle. “How is the oval different from the round?” “It is longer.” “What things do you know that are shaped like the oval?” “An egg, a basket, a bathtub, a dish, etc.”