SAN ANTONIO — For Tira Starr, an eighth grader at Anson Jones Middle School, the plastic nametag hanging around her neck that she has decorated with a smiley face and a purple bat sticker offers a way to reflect her personal flair. For administrators, it is something else entirely: a device that lets them use radio frequency technology — with scanners tucked behind walls and ceilings — to track her whereabouts.

Anson Jones is the first school in San Antonio’s Northside Independent School District to roll out the new nametags, which are part of a pilot program intended to ensure that the district receives all of the state dollars to which it is entitled.

In Texas, school finance is a numbers game: schools receive money based on the number of students counted in their homeroom classes each morning. At Anson Jones, as at other schools, many students were in school but not in homeroom, so they were not counted and the district lost money, said Pascual Gonzalez, a spokesman for the district.

“We were leaving money on the table,” he said, adding that the district expects a $2 million return on an initial investment of $261,000 in the technology at two pilot schools.