[lemming]

But it's not like I sit down and just invent the classes I do with my daughter. There are really good programs, which scaffold all this information and explain it to the kid (and often, coincidentally, to the parent too). For example, I know how to add, but would not know how to go systematically through all the cases and explain them to her. Fortunately the Singapore Math curriculum we use does all that and much much more, and I work through it with her.