Earlier quoted context omitted.
I've always thought his description of the principle behind the New Math was priceless: "In the new approach, as you know, the point is to understand what you're doing, rather than to get the right answer."
Is that a bad thing? I don't make a lot of arithmetic errors in M-x calc or whatever.
It's a bad thing if you never learn how to actually get the right answer. Which unfortunately seemed to be a common consequence of the New Math as a teaching method.