The latest addition to the city’s public relations offensive about the year’s tougher-than-usual state tests is $240,000 in subway, ferry, and newspaper advertisements.

Chancellor Dennis Walcott and his deputies have used a variety of avenues to get out the message about the harder tests in recent weeks, visiting schools, editorial boards and, yesterday, a high-profile church. They have said repeatedly that they expect more students to receive low scores but that they will not penalize students or schools just because the state is raising its standards.

But that hasn’t calmed all fears, and Walcott said he hopes that the ad campaign reaches those who haven’t gotten the message yet.

“By going on subways, the Staten Island ferry, it’s really to reach people where they are,” Walcott said. “It’s to reinforce the exams will be different, more challenging, and test scores will reflect that.”

Standing outside the Barclays Center this morning, not far from one of Brooklyn’s busiest transportation hubs, Walcott showcased the ads and offered details of the ad campaign, which will begin tomorrow — the same day that testing starts. The campaign will end in about 12 weeks, right around the time that the state is expected to release results.

Three versions of the ads — one in Spanish — will cover the walls on 2,000 subway cars and on all five Staten Island ferries. The campaign will also include a newspaper insert that will appear this week in several citywide and community newspapers, including Metro, the Staten Island Advance, and El Diario, the city’s main Spanish-language newspaper. The insert will be published monthly as a newsletter called “Public School Press.”

One ad features a boy shooting a basketball; the other two shows students at their desks doing work. Above the images on each version is the city’s campaign slogan that officials hope will resonate above some of the more negative messaging that’s so far surrounded the new tests: “This Spring We’re Aiming Higher.”

The expected lower test scores are also addressed in the ad copy: ”This spring, state exams for students in grades 3-8 will be different and more challenging. And test scores will reflect that at first.”

The campaign is being funded by a private donation to the Fund for Public Schools by an anonymous donor, whose identity got only one clue today.

“The funder doesn’t want to be identified, but it’s not Michael Bloomberg,” Walcott said.