Cary, N.C. — School is back in session.

About 1.5 million students across North Carolina headed back to the classroom Monday for the first day of traditional-calendar schools, including thousands in the Triangle.

More Info     Get ready to go back to school

The Wake County Public School System, the state's largest school district, expected more than 151,000 students for the 2012-13 school year, including more than 12,000 new kindergartners, in 169 schools. More than 26,000 students on year-round schedules returned to school last month.

In Durham County, school administrators were anticipating about 32,000 students this year. Johnston County schools reported 32,132, and Chatham County Schools reported 7,899 students on the first day and expect that enrollment will reach as many as 8,100 students this year. 

The new year brings with it a new set of curriculum standards called Common Core, which has been adopted in more than 40 states. The aim is to get students to master key concepts and understand how to apply them to real-life situations.

The school year also comes on the heels of a statewide graduation rate that topped 80 percent for the first time.

Wake County school Superintendent Tony Tata said he hopes to continue the improvements that schools made – the district posted gains in proficiency at every grade level and in all but one subject tested.

"We had a good year last year, and so we think we know there a lot of things that have been working," Tata said. "We're analyzing our best practices. We've been doing that through the summer and trying to expand on those things that are truly working for schools."

Continued improvements will come through investments including a $5 million cash infusion for schools to update their technology, such as tablet computers and iPads, he said.

The school system, however, has other challenges outside the classroom.

With about 3,000 to 6,000 new students each year, how to best assign them to schools is still being worked out.

Parents participated for the first time for this school year in process in which they ranked their school choices. But the school board directed school officials to revise the process for the 2013-14 school year, with socio-economic diversity also being factored into the assignment process.

Tata said that the choice-driven plan worked for most families, and he promised that changes to it would be improvements.

"We've got 95 percent of parents exactly where they asked to be and where they want to be," he said. "As we add new students, we’re going to develop a new plan."

Transportation is another challenge, as parents reported long bus rides for their children Monday morning and students being dropped off at wrong sites Monday afternoon.

With 908 buses – 25 fewer than last year to help save money – on the roads, the district says it is working out issues with the routes.