Mayor Bill de Blasio has made no secret of his political differences with Michael Bloomberg, but Thursday he credited his predecessor's administration for contributing to the modest gains by city students in Common Core test scores.

The rate of public school students grades 3 through 8 who were at or above proficiency level in math rose 4.6 percentage points in 2014 over 2013, to 34.2 percent from 29.6 percent, according to Common Core results released Thursday through the city Department of Education. The rate in English increased 2 percentage points, from 28.4 percent to 26.4 percent, results showed.

The new scores reflect half of a school year during which Bloomberg was still mayor, de Blasio said at a news conference in Bedford-Stuyvesant, Brooklyn. He did not mention Bloomberg by name.

"We want to give credit -- the credit's that due to the previous administration for their part of the equation," de Blasio said. "That's only fair and right."

De Blasio added, "It's well known that I disagreed with the previous administration on a number of issues related to education, but it's also important to note some of the things they did right."

Bloomberg invested substantial resources in education and focused on the Common Core curriculum, de Blasio said.

Bloomberg-era schools Chancellor Dennis Walcott in a statement Thursday only addressed test scores from 2013, before de Blasio took office. He made no mention of the de Blasio.

"Today's results show strong gains on state exams for New York City's children," Walcott said. "By giving families quality school choices -- including charters -- and by holding both schools and students accountable for meeting high standards, major progress is possible."

De Blasio and Bloomberg have opposing views on charter schools. Bloomberg supported them as a way to give parents another education choice for their children.

The education department's financial resources need to be more focused on the traditional schools, which serve more than 90 percent of the city's public school students.

His schools chancellor, Carmen Fariña, Thursday said the Common Core scores aren't as high as she would like them to be. De Blasio called the scores "good news," but noted the "immense amount of work ahead" toward further improvement.

Fariña and de Blasio also stressed that standardized test scores should not be the only measure of a school or a student's success and high-stakes testing should be de-emphasized.