I have regular money talks with my 6yr old son. He's not quite old enough to fully understand big numbers (not that an exceptionally large number would be needed to represent our net worth), but we do explain at least the general picture. I.e. we explain that mommy works so we have money for a place to live, food, a car, electricity, vacations, his allowance, etc. We explain that we could have more things, a bigger house, go on more vacations, etc. but it'd require a sacrifice in another area. I.e. a bigger house would mean less vacations and/or mommy having to work more and/or daddy having to work (and most of that money would end up going to childcare). We explain that we prefer experiences to stuff, and that's why he only gets a few presents for Christmas. I even asked him which was more important to him, making memories or more toys; he responded that too many toys would break the house, and that he preferred memories.
So yeah, I'm sure we'll sit down with him when he's older (maybe 10, 12, I dunno) and go over some exact figures. Oh, as for what my parents did...didn't really have any money talks with me. I knew that pay-day equaled allowance day and going-out-to-eat day. Christmas was a decent pile of presents, which caused money worries the next month when credit cards had to be repaid. There really wasn't a discussion of exactly why they were doing what they were doing...not sure why. Seems that it's not quite kosher to speak of money where I grew up except to complain about the bad economy, or the government taking too much of a cut (the lord giveth, the government taketh away). Oh wait, I do remember ONE conversation about money...my dad was telling me how I should get a whole life policy, how great of a deal it was, etc. Fortunately, I didn't follow his advice (though unfortunately, I didn't exactly invest my money elsewhere).