ST. PETERSBURG — Three of the five struggling elementary schools in south St. Petersburg's black neighborhoods have improved their school grades for the first time in years.Maximo Elementary, which had been an F school for five consecutive years, earned a C. Lakewood and Fairmount Park elementaries both got D's, while Melrose and Campbell Park remained F schools.Pinellas superintendent Mike Grego said it was a "great boost" for schools that had been ranked among the bottom 25 of all elementary schools in Florida. With the grades released Friday by the state Department of Education, just Campbell Park and Melrose remained in the lowest 25."We've made tremendous gains in this last year," Grego said.The five schools were at the heart of "Failure Factories," an investigation published last year by the Tampa Bay Times that showed how the district abandoned integration efforts in 2007 and then broke promises of money and resources even as the schools became overwhelmingly poor and black.In the past two years, Grego has poured more money into schools. He added mental health counselors and classroom aides. He created a "transformation team" this year to oversee improvements and assist principals with hiring and behavior management. He also replaced four of the five principals and many of the teachers for the upcoming school year.Ricardo Davis, president of the Concerned Organization for Quality Education of Black Students, said any sign of improvement at the five schools was welcome after so many years of failure."I hope the progress continues and it's sustained," he said.Students in the schools still performed well below their peers on the state's standardized reading and math exams. At Campbell Park, 11 percent of students earned scores this year that were satisfactory or better on the English exam, while 17 percent did so at Melrose, 20 percent at Lakewood, 21 percent at Fairmount Park and 26 percent at Maximo. The average for Pinellas elementary schools was about 51 percent, according to a Times analysis.But Grego said that strong learning gains at some of the schools were a positive sign — and that was reflected in the grades for Maximo, Lakewood and Fairmount Park. "They were successful at moving their students, wherever they were, to a higher level," he said.Learning gains weren't included last year in the state's school grading formula because the test was new. This year, learning gains were included — and the change most benefited predominantly low-income schools in Pinellas.At Maximo, for instance, 26 percent of students earned scores on the English exam that were satisfactory or better. At North Shore Elementary, 50 percent of students did. Both schools earned C's. But Maximo's learning gains were on par with better-ranked schools, such as Shore Acres Elementary and Gulf Beaches Elementary Magnet School, and that gave it a boost in the calculation. With the new grades, three of the five schools also were ranked better than two low-performing Hillsborough schools for the first time in years. Contact Cara Fitzpatrick at [email protected] Follow @Fitz_ly.