Property Class Identifier
Sub Trajectory: classifying

2D Shapes

When operating at the Property Class Identifier developmental level, the child:

Uses class membership for shapes (e.g., to sort or consider shapes “similar”) explicitly based on properties, including angle measure. Is aware of restrictions of transformations and also of the definitions and can integrate the two. Sorts hierarchically, based on properties.

Activities

You may see this:

Other Examples:

Child explains, "I put the 'equilateral triangles' over here, and 'scalene triangles' over here. The 'isosceles triangles' are all these...they included the equilaterals."