You are referring to "new math," which is the kind of math instruction I had when I was a child.

I am reading just now a very interesting book The Mathematics Pre-Service Teachers Need to Know

ftp://math.stanford.edu/pub/papers/milgram/FIE-book.pdf

(posted on

http://hub.mspnet.org/index.cfm/13083

which warns that it may be a slow download)

which describes improved university courses for students who plan to become elementary teachers. That is a big emphasis in the United States now--international comparisons have shown that mathematics education of elementary pupils in the United States is lousy largely because the mathematical education of elementary teachers (at all levels) is lousy,

http://www.ams.org/notices/200502/fea-kenschaft.pdf

so United States mathematicians are trying to do something about that that is more effective than the 1960s attempt at "new math."

Yes, Stillwell's book, mostly aimed at mathematics students who will go on to be mathematicians rather than schoolteachers, is also an outcome of thinking about curriculum reform. He describes his motivation for writing his excellent book as attempting to understanding concepts of mathematics he still didn't understand after he earned his Ph.D. at MIT.