In 1989 NCTM published the landmark document Curriculum and Evaluation Standards for School Mathematics. This publication represented a historically important first attempt by a professional organization to develop and articulate explicit and extensive goals for teachers and policy makers. In 2000 NCTM published Principles and Standards for School Mathematics as a guide for all who make decisions that affect the mathematics education of students in prekindergarten through grade 12. These two publications make an argument for the importance of understanding in learning mathematics and excerpts regarding the teaching of fractions with understanding are contained in the following two files.
NCTM's Standards 2000
NCTM's Standards 1989