Give them the biggest line of bullshit to see if they catch on. Another good teaching is to steal some of their snacks and tell them you are taking taxes. When they get older they should be able to tell when both are bullshit.
Discussion
I like this...
We have a very socratic way of solving problems with the kids, we almost NEVER answer a question with an answer... alsways with another question.
But sometimes we answer with a truth that contains a small lie to see if they are catching on...