Let's do our kids the favor of taking the mystery out of money.
There are plenty of people who think that money isn't an appropriate topic for kids, especially very young kids. I'm not one of them; I think that money is a topic that's surrounded by a ton of secrecy in our society - even close friends and family members often don't discuss finances with each other - and that all that secrecy does is make people feel even more at sea about a topic that is likely already a pretty big stressor in their lives.
For the past few months, we've been testing out different ways of instituting a reward system with our five-year-old son (three weeks of not biting nails = a small toy; clearing your dish every night for a week = 25 cents), but none of them have felt quite right, mostly because it's been difficult getting him to understand that a quarter means something; it's not just an odd, shiny toy to play with. And besides, I'm sort of from the "kids should help out and do the right thing because that's what they should do, not because they're being paid for it" school of thought, so rewarding our son for chores and such has always felt a little odd to me.