"The algorithms are good ONLY if you can convince the parents to learn them and not "secretly" teach the old way to their kid. I haven't been successful even though I make great efforts to communicate that."
-- elementary school teacher
Ironically, this teacher does not consider the inefficiencies of the multiple algorithms to be the problem, nor even the lack of mastery required for any one algorithm in particular. Instead, she seems to perceive that these algorithms fail because of meddlesome parents who can't control themselves from wanting their children to master the foundations of mathematics. Sheesh.
How dare we teach our children mathematic algorithms that are efficient, consistent and actually work. The nerve!