La Texican, I totally agree. For example, I was pretty upset when I found out that my wife had "helped" my son understand how to do a certain kind of problem (making the largest or smallest positive number using a collection of digits). I felt like she'd robbed him of the chance to figure it out on his own-- after that actually doing the problems is essentially make-work. I was quite despondent over something that probably seemed really trivial at the time!
I also won't let his grandmother do anything learning-wise with him when one of us is not around, because she has a strong tendency to "help" him, even when he doesn't ask for it.
With learning math and problem-solving skills, basically my main approach is to find something that's a little beyond his easy grasp, but which I think he can figure out on his own with a little intense focus. My hope is that this will result in lasting superb self-confidence in addition to increasing his general problem-solving skills, and so far it seems to be going that way.
I dunno what I'd do with the conservation / counting idea. It seems to me that telling him to count up the units is really giving him the answer. I think I would tend to just teach him (or learn him) how to do area, and wait for him to realize on his own that the little regions can all be added up, or something, leading to the general concept of conservation. I think it would happen naturally then, and he'd be allowed to discover it. I just know that after DS5 had learned a fair bit about area, conservation was a no-brainer.
