Sixty educators from across the nation roamed the halls and ringed the rooms of East Mooresville Intermediate School, searching for the secret formula. They found it in Erin Holsinger’s fifth-grade math class. There, a boy peering into his school-issued MacBook blitzed through fractions by himself, determined to reach sixth-grade work by winter. Three desks away, a girl was struggling with basic multiplication — only 29 percent right, her screen said — and Ms. Holsinger knelt beside her to assist. Curiosity was fed and embarrassment avoided, as teacher connected with student through emotion far more than Wi-Fi. “This is not about the technology,” Mark Edwards, superintendent of Mooresville Graded School District, would tell the visitors later over lunch. “It’s not about the box. It’s about changing the culture of instruction — preparing students for their future, not our past.” As debate continues over whether schools invest wisely in technology — and whether it measurably improves student achievement — Mooresville, a modest community about 20 miles north of Charlotte best known as home to several Nascar teams and drivers, has quietly emerged as the de facto national model of the digital school. Mr. Edwards spoke on a White House panel in September, and federal Department of Education officials often cite Mooresville as a symbolic success. Overwhelmed by requests to view the programs in action, the district now herds visitors into groups of 60 for monthly demonstrations; the waiting list stretches to April. What they are looking for is an explanation for the steady gains Mooresville has made since issuing laptops three years ago to the 4,400 4th through 12th graders in five schools (three K-3 schools are not part of the program). The district’s graduation rate was 91 percent in 2011, up from 80 percent in 2008. On state tests in reading, math and science, an average of 88 percent of students across grades and subjects met proficiency standards, compared with 73 percent three years ago. Attendance is up, dropouts are down. Mooresville ranks 100th out of 115 districts in North Carolina in terms of dollars spent per student — $7,415.89 a year — but it is now third in test scores and second in graduation rates. “Other districts are doing things, but what we see in Mooresville is the whole package: using the budget, innovating, using data, involvement with the community and leadership,” said Karen Cator, a former Apple executive who is director of educational technology for the United States Department of Education. “There are lessons to be learned.” Start with math lessons: each student’s MacBook Air is leased from Apple for $215 a year, including warranty, for a total of $1 million; an additional $100,000 a year goes for software. Terry Haas, the district’s chief financial officer, said the money was freed up through “incredibly tough decisions.” Sixty-five jobs were eliminated, including 37 teachers, which resulted in larger class sizes — in middle schools, it is 30 instead of 18 — but district officials say they can be more efficiently managed because of the technology. Some costly items had become obsolete (like computer labs), though getting rid of others tested the willingness of teachers to embrace the new day: who needs globes in the age of Google Earth? Families pay $50 a year to subsidize computer repairs, though the fee is waived for those who cannot afford it, about 18 percent of them. Similarly, the district has negotiated a deal so that those without broadband Internet access can buy it for $9.99 a month. Mr. Edwards said the technology had helped close racial performance gaps in a district where 27 percent of the students are minorities and 40 percent are poor enough to receive free or reduced-price lunches.