The latest report cards for Louisiana public high schools, released Thursday, were almost uniformly good news for schools in the Baton Rouge metro area, with several improving whole letter grades and climbing in state rankings.

Three of the 10 most-improved high schools in 2015 are in and around Baton Rouge: Mentorship Academy, as well as Baker and West Feliciana high schools. All three improved a letter grade.

High schools are assigned grades based on how students fare in five areas: core courses, ACT results, graduation rates, college readiness and other diploma enhancements, and gains by struggling students. Those five areas are used to compute a school performance score, ranging from 0 to 150 points. Schools that come in at 100 or above earn an A, while schools at 50 or below usually earn an F.

Baker High School went from a solid D to a high C. The high school’s 24.2-point leap was the fourth-highest in the state. The school increased in all five areas measured.

“We have a perfect opportunity to do great things here,” said Principal Traci Morgan. “We are a diamond in the rough.”

Morgan, who became principal in 2010, credited part of the improvement to a more effective approach to preparation for the ACT college placement exam, including better training of teachers and a Saturday boot camp for students.

Like many high schools, Baker High is trying to make better use of technology. Without the money to buy tablets or laptops for its students, the high school is harnessing technology students bring with them already: their cellphones.

Kelly Haynes’ sophomore biology students on Thursday were finishing up a unit examining the ways cells divide, specifically teasing out the differences between the similar-sounding processes of mitosis and meiosis.

Soon after class starts, Haynes divides students into small groups and allows them to pull out their cellphones to do Internet research. On the door of her classroom is a sign saying, “Cell Phones in Use.” Haynes notes how much more information is available today than when she was in school, and she wants the students to know how to find it.

“It’s not just what I say,” she said, “it’s where I can send them to find out what others say.”

Roughly half of Baker High’s class of 2015 earned an 18 or above on the ACT. The maximum score on the test is 36. A year before, less than a quarter of the graduating class reached the score of 18, which is the minimum a student must earn to qualify for one of the state’s Taylor Opportunity Program for Students scholarships. Baker High’s composite score on the ACT improved from 15.6 to 17.5, the second-best improvement in the state.

The most-improved school in the state’s report cards was KIPP Leadership Academy in New Orleans, which went from a D to B, one of three high schools to jump two letter grades.

The second most-improved school, Mentorship Academy, is a more complicated story. The downtown Baton Rouge charter school, which opened in 2010, until recently was two schools in one: one focusing on science and technology, the other on digital arts. Both schools improved a lot in the latest report cards, though it was the digital animation school that improved the most.

The improvement at the twin schools is largely attributable to the new schools finally having graduates to earn them points to lift their graduation rates. This summer, the two Mentorship academies merged into one school.

West Feliciana High School was the 10th most-improved school, with its letter grade jumping from a B to an A. Its school performance score was 17th across the state; last year, the high school ranked 37th.

A total of 171 public high schools received report cards Thursday. They are being released much earlier than elementary and middle schools, which won’t come out until December.

Almost 80 percent of high schools improved over their performance compared with a year ago. Thirty-six schools declined.

The Baton Rouge metro area was home to two of the 10 schools most in decline: Port Allen and Glen Oaks high schools, whose performance scores slipped 6.9 and 6.6 points, respectively.

Five of East Baton Rouge Parish’s 12 high schools lost ground: Belaire, Glen Oaks and Tara now have low D’s and are in danger of becoming F schools if they don’t improve. Also losing ground were Broadmoor High and Northdale Superintendent’s Academy, which had a D and F, respectively.

Besides Mentorship, McKinley High was the most-improved school in the district, improving 9.1 points.

Career Academy would have been another much-improved school for the East Baton Rouge Parish school system. The small charter high school, however, was closed in May, after just four years in operation. Its first graduating class, much like Mentorship Academy, lifted Career Academy’s score an impressive 31.5 points, but the improvement still left the high school with a high F grade.

Nancy Roberts, a founder of the school and executive director of the Louisiana Resource Center for Educators, had predicted a good increase this year if the school were allowed to stay open. She said she’s not surprised at Thursday’s results. She noted that the school system has closed schools before, including EBR Lab School in 2012, only to find out later their scores had improved significantly.

“It’s like being in ‘Groundhog Day,’ ” Roberts said, alluding to the 1992 movie.

Four new high schools, which opened in fall 2014, received their first report cards Thursday. Three earned Fs and one a D. One of those was Capitol High, now run by Washington, D.C.-based charter school group Friendship Schools. It earned a low F of 15.9 points after its first year. That was the third-lowest score in the state for a high school.

Gains by struggling students, known as progress points, can add as much as 10 points to a school’s performance score. More than half of the state’s high schools earned progress points this year compared with just 4 percent a year ago. Thirty-five of the 40 A-rated high schools in Louisiana earned progress points. Locally, A-rated Denham Springs, Live Oak and Walker high schools all earned the max of 10 extra points.

The top-rated high school in the state was Ben Franklin High in New Orleans. This perennial top public school was followed by Baton Rouge Magnet High, which moved up two spots past Louisiana School for Math, Science & The Arts in Natchitoches and Thomas Jefferson High School for Advanced Studies in Gretna.