Oh boy - you haven’t seen a Common Core elementary textbook lately. Don’t get me wrong; there are some good things in Common Core math. But they took a great idea from research and warped it. Researchers like Constance Kamii said to let students use their own ideas to create strategies for adding multi-digit numbers (and other operations) before or instead of teaching the standard algorithm. The Common Core textbooks have turned that into the idea of directly teaching several different strategies, all of which end up with the same answer, and only teaching the standard algorithm at the very end. But kids are supposed to memorize these other strategies even if they don’t make sense to them. It steams me - I’m a math educator, and the most important thing to me is that math makes sense.
If you want to see an example of this, check out one textbook series.
