you did not have to actually know any multiplication. and the rules for are hung on a visual framework instead of just being "the rules."
No one said it was revolutionary (well maybe some youtube commenters..)
But this line thing... this is a trick. And, might I add, a trick that may actually cause more work and use up more scratch-paper space for the figurer. Using a "visual framework" without meaning is no way to teach math. The point is that the standard algorithm is the shortest path from point A to point B, and that is why it should be taught first and foremost.
This is just a visual metaphor for standard mutiplicaton process. They are fundamentally the same thing. I personally think the way in the video has the potential to help children assimilate the process faster and/or better than otherwise.
But please explain to a child the difference between abstract rules and directly derivable properties of distributivity of multiplication over addition. See how much of a difference there is to a first grader between "It's a fundamental property of mathematics" and "Because I said so."
>But this line thing... this is a trick.
Yes, yes it is. And seeing as all any one has said is it's a elegant (under certain circumstances) trick, why are you so hostile. No one here has proposed replacing the k-12 math curriculum with happy fun line counting time.
EDIT: okay the sibling post may have said something that could possibly be construed as supporting the addition of this to the standard curriculum. Still not advocating replacement.