An Iowa woman jokingly calls it 'Satan's handiwork.' A California mom says she's broken down in tears. A Pennsylvania parent says it 'makes my blood boil.' What could be so horrible? Grade-school math ...

Model math standards produced by conservative education advocates helped spark a battle in South Dakota that could spread to other states.

Add Yahoo as a preferred source to see more of our stories on Google. Fifteen years after the calamitous rollout of the Common Core math standards, the once-derided strategy has proven its staying ...