For questions about the New Math school reforms introduced in the United States and Europe during the 1960s.
"New Math" refers to a wave of mathematics curricular reforms launched in the late 1950s and throughout the 1960s, primarily in the United States and Europe. New Math curricula were characterized by the introduction of modern vocabulary and theoretical foundations; for example, the language of sets, functions, etc. was woven into the curriculum at all level.
At the elementary level, New Math texts emphasized the difference between numbers and numerals, and introduced students to different number-base numeration systems. At more advanced levels, many New Math textbooks emphasized rigorous proof, and some taught the basics of abstract algebra (e.g. groups, rings, and fields). Some of the innovations of the New Math (e.g. inequalities and simple matrix operations) remain as standard components of the curriculum today.
For a more detailed description see also http://en.wikipedia.org/wiki/New_Math.