Redux

I get that, but I guess my issue comes from the whole if it ain't broke line of thinking. If number sense and computation strategy is a lesson goal, why alter basic addition/subtraction and not form a method to itself to teach that. Perhaps I'm overthinking it, but it seems like it could do more confusion than good.

I haven't seen it, but I really don't think anyone is going to have any trouble with 32-10. 2-digit arithmetic is small fry.

Kids today can't find America on a globe or spell America. Making math more complicated is probably not the first issue needing addressing.