When Philadelphia public school students head back to class Tuesday, there will be more counselors, more enrichment activities, and more teachers to reduce class sizes in the early grades.

High school students will see an extra period in their day and a new requirement to map out their plan to graduate on time.

For the district's 95 lowest-performing schools, there will be more support and closer monitoring. There will be more spots for preschool-age children and more places for students at risk of dropping out.

The initiatives - $126 million worth - come as a result of Imagine 2014, Superintendent Arlene Ackerman's blueprint for the next five years in the Philadelphia School District. Officials haven't released the full, five-year cost of the plan, which eventually will close up to 35 failing schools and reopen them as charters or turn them over to private managers. "We believe this is the blueprint for accelerating our achievement," Ackerman said in an interview last week. "We're very excited for the school year to begin."

The biggest investment, $32.5 million, aims to reduce class sizes in kindergarten through third grade. The maximum, previously 30, is now between 20 and 26, depending on the grade and whether the school is an "empowerment," or failing, school.

"We are hopeful that the smaller class size will mean more interaction with students," Ackerman said.

The district is spending $18.5 million to lower the student-counselor ratio to 300-1 in high schools and 250-1 in middle schools. (It used to be 500-1 in both.) The new counselors will be concentrated in neighborhood high schools, and most will be assigned to freshmen, who will be required to write plans to help them graduate on time.

The neighborhood high schools also will get new schedules, including more electives and an extra period (the other periods will be shortened) to help struggling students catch up and to enrich students performing at grade level. Student Success Centers, where teenagers can get information about college and work, will be expanded.

Programs targeting potential dropouts will be expanded. The district will fund more alternative-education slots, many for students who are overage and undercredited - 17 and still freshmen, for example. There are about 6,000 such students, Ackerman said.

The district has drawn criticism for cutting the seats for students with disciplinary problems from 3,150 to 2,240.

The district is also restarting in-school suspension, which had been discontinued.

In all, the district has 161,500 students, down from 167,000 last year.

On tap are intramural programs for students in the middle grades, peer mediation at middle and high schools, more slots for early-childhood-education students, and staff for the in-school suspensions.

And, yes, there will be enough textbooks this year, Ackerman said. They were a hot-button issue last year, with a shortage of proper classroom materials at some schools.

Every day, to prepare for the year, the superintendent and some of her staff are reviewing the buildings and supplies at every school, and there should be no problems this year, she said.

"If any school doesn't have books, I'm going straight to that principal," Ackerman said. "That shouldn't happen."

Central office staff have been making spot-checks at schools to ensure things are running smoothly, and that will continue throughout the year, Ackerman said.

Changes are also afoot for the empowerment schools, the 95 lowest-performing schools. And although the district paid careful attention to those schools last year, they should expect even more scrutiny this year, said Ackerman, who has taken direct control of them.

"There's going to be a lot more monitoring, a lot more professional development for the teachers and principals," she said. "There'll be a lot more supervision."

The empowerment schools will get reading specialists and much more curriculum direction from the central office, and their students will have 45 extra minutes of reading and math instruction, Ackerman said.

Teachers districtwide will have new resources, the superintendent said. A new office of teacher affairs will support them, and a peer-assistance program will provide mentors for new and struggling educators.

About 1,300 new teachers and 30 new principals will start the school year. Before she arrived, Ackerman said, too few principals and teachers were disciplined for poor performance. About 100 teachers and more than 30 principals were rated unsatisfactory last year, she said.

The removed principals haven't been sent to central-office jobs, as was the practice in the past, Ackerman said. "We're not going to reward them for poor performance," she said. Instead, they've been sent back to classrooms as assistant principals or teachers, she said.

Ackerman plans to open the year Tuesday with a bell-ringing ceremony at Fels High School, one of the two new buildings in the district.

Contact staff writer Kristen Graham at 215-854-5146 or kgraham@phillynews.com.