Mackenzie Geiger, left, explains her thinking to Cameron Tormone on a math problem in Dana Snapp's class at Fuquay-Varina Elementary School. Students there have been using Common Core Math for the ...

WESTERLY, R.I. -- Any adult who has tried to help a second-grader with homework has noticed math is not what it used to be. Now schools are unlocking the secrets of Common Core math for mystified ...