The NC Department of Public Instruction explains how national and state standards work together (kinda).

North Carolina has signed on to a consortium of 48 states that is working jointly towards developing and adopting a common set of K-12 standards in Mathematics and English Language Arts. The K-12 Math Essential Standards and the English II Essential Standards that were adopted by the State Board of education last September will be updated to incorporate the Common Core standards, and these standards will be submitted to the State Board for adoption in late spring. (Emphasis added)

So here is what happened:

1. North Carolina joined a National Governors Association consortium of states working toward Common Core standards

2. The state adopted new math and English standards written by staff at the NC Department of Public Instruction

3. The NC State Board of Education approved the new standards

4. The National Governors Association released the Common Core standards

5. NC Department of Public Instruction will revise the adopted standards to incorporate the Common Core standards

6. These new standards will go back to the State Board of Education for approval

Why were steps 2 and 3 necessary at all? Good question.