and gone are the days of memorizing multiplication and division tables... without a calculator they are lost, and even with one they write down whatever it says not knowing it might be off by an order of magnitude because they punched in a number wrong and have no foundation to rely on, they just write it down cause THEY and the calculator are NEVER WRONG!!!
Before he was in kindergarten, my son knew multiplication tables up to 15 x 15 and could read. He grew up to get a PhD in mechanical engineering.
That's the major root problem. I grew up listening to sing-song-ey records (45's) that went through the multiplication tables up to 12x12. You can't find anything like that for kids nowadays. And their math workbooks introduce concepts too early without basics, IMHO.