While the concept of moving to a longer school year for students in kindergarten through 12th grades “makes sense” to President Obama, the top administrator for Lawrence public schools isn’t buying in.

Not until the district gets more money, anyway.

“The most difficult challenge to overcome is cost, because extending the school day or the school year means you have to pay people more,” Superintendent Rick Doll said.

Doll joined millions of Americans in watching Obama address education issues during a 30-minute television interview Monday. And while Doll agrees with the basis behind Obama’s call for a longer school year — that U.S. students attend class, on average, about a month less than children in most other developed countries — he knows the topic won’t gain enough momentum to spur local change in the coming year.

“We’re just trying to maintain what we’ve got,” Doll said. “The reality of the matter is, in the short term, that’s not on our radar screen.”

During an interview on NBC, Obama did not specify how long a school year should be. But the president indicated that being in school for another month, as is the case in many other countries, could be worthwhile.

“That month makes a difference,” Obama said. “It means that kids are losing a lot of what they learn during the school year during the summer. It’s especially severe for poorer kids who may not see as many books in the house during the summers, aren’t getting as many educational opportunities.”

Testing in Lawrence public schools shows that students generally hold even or drop slightly in math and reading performance between grade levels. The gap widens for at-risk students, said Kim Bodensteiner, the district’s chief academic officer.

“It might take a month, six weeks or longer to get a student back to the skill level they had the previous spring,” Bodensteiner said. “More and more years in a row of that happening, students who don’t have as many enrichment opportunities just get farther and farther behind.”

High-schoolers in Lawrence have 175 in-classroom days each year, just short of the U.S. average of 180 reported last year by the Education Commission of the States. The average is 196 for students in countries with the best achievement levels, including Japan, Korea, Germany and New Zealand.

Estimated cost for adding a month of instruction in Lawrence public schools: $6.5 million to $7 million, Bodensteiner said, or at least $325,000 per day.

“It’s a pretty eye-opening amount, just to open the doors for a day,” she said.