example of a scaffold à la Vygotsky

Vygotsky wrote about the zone of proximal development. Scaffolds are then used to pull a child from his level to a higher level of thinking / reasonning / understanding.
An example of a scaffold would be what I did at the swimming pool the other day.
situation:
My son is 4 years old. He was the first in a row but went outside for a while and then returned. Then he complained that he was first to the boy who had taken his place in the line. "it's not fair, I was first." I told him that he can expect people to take his place when he goes away. Now the boy who was first left. My son quickly went back first in line. Now I asked him if he thinks that's fair. The other boys comes back and sees his place is taken and complains. I then say: "but before you thought it was fair to take the place of someone else." Then a discussion starts about that sometimes you're first, and sometimes you're second.

The scaffold in this case was that I made a connection to cars and place in a sequence. I said you can put a yellow car first, second or third, or a blue car, or a red one. You can look at how many different places you can put a car in a row.

Now I can use this scaffold in the future to talk about an honest system of giving every child a turn, I can use this to teach morality, I can use this to teach principles of combinatorics.