Pink Tower Activity
Invite the child to your learning area with a mat and stackable blocks.  The blocks should not be in any order.  Select the largest and smallest.  Allow the child to explore as you point out their differences.  Next, build a tower using all of the blocks.  Point out to the child that you are using the largest block in the pile.  Demonstrate how to add blocks to the tower, then disassemble the tower. 
The goal of this activity is education of visual perception related to size, development of visual-motor control, and fine motor coordination.

Variations of this activity include:
Centering the cubes on top of the preceeding cube
Building horizontally
Building diagonally
Break the sequence to see if the child notices the break
Group participation
Building with two sets