With the new school year comes some new school policies, and on Thursday Mayor Bill de Blasio took part in a five borough tour to tout the benefits.

It was the first day back for all city schools, pre-K classes, and the brand new 3-K program.

It is part of the expansion of pre-kindergarten, starting this year with 1,600 three-year olds in the South Bronx and Brooklyn.

Speaking at PS 277, the mayor said 3-K gives kids a critical foundation for future learning, while saving parents thousands on child care.

"If you don't have a good option for your kids, you end up turning to a friend, a neighbor, a relative. And they're gonna be there for you, but it's not the same thing as a child getting an education," de Blasio said.

This is also the first year that all children will have access to free school lunch, regardless of their family income.

Running for re-election, with the Democratic primary just five days away, de Blasio turned a spotlight on his expansion of early childhood education.

"This never existed before! Never existed! It was a dream," de Blasio said at a press conference. "When we started pre-k, we knew that would be tough to be put together, and everyone worked so hard to achieve it. And then we started dreaming some more."

De Blasio also highlighted some of his other initiatives: Computer science for all, the expansion of Advanced Placement courses, and universal free school lunch.

What was not mentioned, however, are the challenges that are buffeting the system. The mayor spoke with honors students at August Martin High School in Queens, one of the struggling schools that could face closure next spring. Its graduation rate remains low despite receiving more resources under the mayor's $600 million renewal program.

Nor was there mention of the de Blasio's new plan to address racial segregation in schools, a blueprint widely criticized as a weak response to an enduring problem.