This op-ed piece gives a historical perspective on curriculum change.
Robert Reys, email@example.com, is Curators' Professor of Mathematics Education at the University of Missouri in Columbia, where he teaches undergraduate students preparing to be high school mathematics teachers as well as graduate students. Mathematics curriculum is one of his areas of interest.
Barbara Reys, firstname.lastname@example.org, is Lois Knowles Distinguished Professor of Mathematics Education at the University of Missouri and director of the Center for the Study of Mathematics Curriculum. She teaches both undergraduate and graduate courses in mathematics education.