Al wrote: > ... imagine if we showed > kids pictures of Saint Bernards exclusively with the > label "dog" for the first 7 years of their lives. > Then trying to convince them that a Chihuahua is a > "dog" too will be a difficult process. Yet that's > what we do with quadrilaterals all the time - no > wonder everyone gets confused!
There is a similar problem mentioned in the recent NRC report on Math. Learning in Early Childhood.
Most triangles shown to or played with by preschoolers are equilateral, often paired or tripled with a circle and a square.
When I asked some Pre-K teachers recently to draw a circle, a square, and a triangle, only one triangle was non-equilateral, and it was isoceles. All triangles and all squares were drawn with a horizontal bottom edge, the way it is stable to put a square block on a table.
There is now an effort in pre-K to show kids triangles of different shapes, and figures in different orientations.