Little Chef number 2 has an inherent sense of fairness, if his sister gets a treat, he must get one too, if her treat is bigger than his, that entitles him to take two of his. Imagine her eating a small chocolate bar, and him insisting on two Hershey's kisses - to be fair.
Today, while reading one of his storybooks, the character and his family cleaned up the house and packed a box full of toys.
Me: What would you do with a box of your old toys?
Alex: Sell them!
Me: What else could you do with them?
Alex: Throw them in the trash (tempting)
Me: What if you knew someone that didn't have toys? what could you do then?
Alex: Sell them to them.
Alex: We paid money for the toys, they should pay money too. That's fair.
Me: What if they didn't have any money?
Lots of thinking....
Alex: We could give them a toy. We could sell a toy to children who have money, and give a toy to those that don't.
Seems fair play to me.