Chicago elementary school students posted some of their biggest one-year gains ever on the state ISAT tests they took in the spring.

Preliminary results released by Chicago Public Schools Friday show scores improved in every grade and subject. The test is taken by students in third through eighth grades.

Nearly 70 percent of CPS students now meet reading standards. For math it’s nearly 80 percent.

Schools CEO Jean-Claude Brizard said the test score results represent “a little bit of good news.”

But he said he’s troubled by scores from a more rigorous test, the EXPLORE, that show most eighth graders are not on course for college. On that exam, just 20 percent of Chicago eighth graders hit college readiness targets in math; 31 percent hit the targets in reading.

Brizard immediately connected those troubling numbers to Mayor Rahm Emanuel’s call for a longer school day.

“We need much more time, not just during the school day, but a much longer school year. We have a lot of kids who are falling off our pipeline that we have to bring into the fold. And we can’t do this with the kind of time allotment we have right now,” he said.

The district is also concerned about deep and widening performance disparities based on race. Among white students, 42.7 percent exceed standards on the ISAT.  Just 15.5 percent of Latino students and 11.3 percent of black students exceed standards.

White students are disproportionately enrolled in what are seen as the best schools in the system.

Chief Education Officer Noemi Donoso said the district was not highlighting bad news when it came to test score improvements. Under Mayor Richard Daley’s administration, gains like the ones released by the district Friday would have occasioned a mayoral press conference at a school.

“It’s not about spinning the data,” said Donoso. “You look at the EXPLORE data, you look at our high school graduation rates, and you look at our ACT data. We need to do a far better job of providing our students with the support they need and the rigor in the classrooms that they need to be ready for college.”

Researchers have found, and state officials have acknowledged, that students who simply meet standards on the ISAT, as opposed to exceeding them, will likely not be qualified to attend a four-year college.  

District officials, who are just beginning to analyze the numbers, pointed to turnaround schools as posting particularly good scores. Turnarounds are chronically underperforming schools where all staff was let go; many of those schools are now managed by the nonprofit Academy for Urban School Leadership.

Morton School of Excellence, an AUSL turnaround school on the West Side, posted the second highest gains in the city.

“So we went from 45 percent of the kids meeting and exceeding to almost 76 percent,” said principal Angel Turner. It’s Morton’s second year of double-digit test-score gains.

Turner said she did it by making sure there was a highly effective teacher in every classroom. The school had every teacher target groups of children they could move to the “meets standards” and “exceeds standards” categories.

Morton’s staff celebrated the school’s soaring test results: they bought Turner and the assistant principal a helicopter ride above Chicago and lunch at Trump Tower.