'Common core standards': education reform that makes sense
Editorial/Los Angeles Times
In many third-grade classrooms in California, students are taught — briefly — about obtuse and acute angles. They have no way to comprehend this lesson fully. Their math training so far hasn't taught them the concepts involved. They haven't learned what a degree is or that a circle has 360 of them. They haven't learned division, so they can't divide 360 by 4 to determine that a right angle is 90 degrees, and thus understand that an acute angle is less than 90 degrees and an obtuse angle more. (more...)