If they _had_ learned the concepts, they would have no trouble understanding their kids' new homework.
Not so.
I understand the concepts perfectly well. The problem that I have is that there are multiple ways that I can map my understanding of the problem to the needlessly overcomplicated homework question in front of me. And if I can't figure out which of those ways matches what my child was taught, I can't tell my child which pointless and silly way of answering it is the "right" one.
You can object that this is opposite to the intent of the Common Core initiative. But it doesn't change the fact that this is the implementation of the Common Core initiative that my children actually have to deal with.
Not so.
I understand the concepts perfectly well. The problem that I have is that there are multiple ways that I can map my understanding of the problem to the needlessly overcomplicated homework question in front of me. And if I can't figure out which of those ways matches what my child was taught, I can't tell my child which pointless and silly way of answering it is the "right" one.
You can object that this is opposite to the intent of the Common Core initiative. But it doesn't change the fact that this is the implementation of the Common Core initiative that my children actually have to deal with.