Piaget's theory of cognitive development. Really interesting!!!!!!!

I think that this video is so interesting in order to understand what is thePiaget's theory of development.
Here we can observe some qualities of different stage for explame in this video . We can observe how this girl at the first time saw the two lines of the coins,count them and know that in the two lines are the same number of coins, then when the istructor repart the same coins but in two different lines and did one more longer, the kid think that thereare more coins in a longerspace than the other.