The performance gap between Chicago’s black and white students — and between its poorest students and their wealthier classmates — continues to widen, newly released data show

Black Chicago Public Schools students fell further behind whites in three of four key measures, according to the 2013 National Assessment of Educational Progress, often called the Nation’s Report Card. And students who qualify for free school lunches — traditionally a measure of poverty — also fell behind in three of the four tests of grade- and middle-school kids’ ability in reading and math. CPS has identified four priority groups that have become the focus for improvement: blacks, Latinos, students learning English and those with disabilities. The report shows that despite steady improvements over the last decade, Chicago still lags behind most major U.S. cities in math and reading at the fourth- and eighth-grade levels. The gap in fourth-grade math test scores between black and white students in Chicago widened to 40 points — the largest gap since the national study began in 2003, and significantly wider than the 31-point gap in the average major U.S. city. Though the average white student was graded as “proficient” with “solid academic performance” in fourth-grade math, the average black student was just over the threshold for “basic” understanding, or a “partial mastery” at that stage, according to the report. About 8,000 CPS students participated in the test, which is administered every two years.