The Common Core State Standards may "share many features and concepts with existing standards" but "the new standards also represent a substantial departure from current practice in a number of respects."
This post looks at the differences in Mathematics and ELA, providing an explanation with some details for each difference.
In Mathematics the differences listed are;
* Greater Focus
* Coherence
* Skills, Understanding, and Application
* Emphasis on Practices
In English Language Arts the differences listed are:
* More Nonfiction
* Focus on Evidence
* "Staircase" of Text Complexity
* Speaking and Listening
* Literacy in the Content Area