Short about 300 teachers, 82 mobile classrooms and one kitchen, Charlotte-Mecklenburg Schools officials said Wednesday they are prepared for the switch to grade K-8 schools and don't expect problems with the format.

During a back-to-school news conference held at Druid Hills Academy, one of eight former K-5 elementary schools that will switch to a K-8 format for the 2011-12 academic year, interim Superintendent Hugh Hattabaugh and other school officials say they are prepared to teach elementary and middle school students at the same site.

"We're moving in the right direction -- we've done the right thing," Hattabaugh said.

But CMS will start the school year a week from Thursday with plenty of teaching vacancies and dozens of mobile classroom units not in place. Hattabaugh and other officials blamed that problem on last-minute factors that couldn't be planned in advance.

The switch to a K-8 format was one of several ways in which CMS adjusted to budget cuts this year. The system closed 11 schools, mostly in low-income areas, and distributed those students to other sites. Many of those students were moved to the new K-8 sites -- Ashley Park, Berryhill, Bruns Avenue, Walter G. Byers, Druid Hills, Reid Park, Thomasboro and Westerly Hills.

That decision prompted concern from some people that having young children in the same school and on the same buses with teens could create problems.

Ann Clark, the system's chief academic officer, said teachers and other staff members have undergone training to deal with the new situation. She said staff members will be especially vigilant in the hallways and during lunch periods. Clark also said the schools have been set up to give the middle school students a feeling of "being separated" from their younger counterparts.

"There are also exciting opportunities -- mentoring and buddying, for example -- that weren't available in the old format," Clark said.

Carol Stamper, CMS' executive director of transportation, said the school system also has taken care to guarantee safety of students on buses.

"It's not like we don't have experience, transporting students to K-8 schools," she said, referring to Smith, Collinswood and Oaklawn language academies, which have housed elementary and middle school students for several years.

But, she added, CMS has identified its best bus drivers and has assigned them to the K-8 schools.

"We will have strong, experienced drivers for those schools," she said. "In addition, we will seat the younger students in front and older students in the back. That will be enforced strictly."

Across the system -- regardless of the grade level -- CMS will deal with teacher vacancies at the start of the school year.

Dan Habrat, the human resources director for the system, said about 300 teacher vacancies are expected next week, although new teachers have been hired in about half of those cases. About 150 to 200 teachers will not be ready for the start of the academic year because they gave notice to their old school systems within the last 30 days, or they have not completed the necessary paperwork.

Habrat said that as of Wednesday, there were about 150 vacancies.

"We are taking the time to screen our candidates," he said. "We would rather open the year without a teacher in the classroom, if it means hiring the best possible educator."

Habrat said CMS will have about 9,700 teachers this year -- 500 more than last school year.

Some mobile classrooms won't be ready for the start of classes either. It was July before CMS learned how many teaching positions it would be granted by the General Assembly, and the number was larger than expected. That meant, said Associate Superintendent Guy Chamberlain, that CMS had to get 82 "retired" mobile classrooms ready for use again.

Chamberlain said only about 15 of those classrooms can be moved per week, so it probably will be October before the last of the units is installed at its new site.

And there is the matter of an unfinished kitchen, Chamberlain said.

That is at Cochrane Middle School, where a cafeteria renovation and expansion project is near completion. Chamberlain said that project will be completed about a week after classes begin.

"Students will receive boxed lunches for the first week," he said.

School officials said they expect about 141,000 students this year -- an increase of 2,500 from the 2010-11 academic year.