National test scores show Minnesota's eighth graders were the top math performers in the country last year, and fourth graders did nearly as well. In addition, results of the National Assessment of Educational Progress rank Minnesota students well above the national average in reading scores for both grade levels. But the scores also provide more evidence that the performance of minority and low income students still lag behind that of their peers. State education officials are trying to find ways to tackle the lingering achievement gap this week at a conference in Minneapolis. Minnesota Public Radio's Tim Pugmire reports...