Enrollment in the Lawrence school district grew slightly more than budget officials had projected earlier this summer, which means they’ll have about $57,000 more to spend in the current school year than they had budgeted in August.

That’s a relatively small amount within the district’s total budget of about $141 million.

School board members were briefed on the semi-official enrollment numbers during their meeting Tuesday night.

According to the head-count of enrollment taken Sept. 20, there were 11,458 students enrolled, either full time or part time, in Lawrence public schools.

That includes 9,998 students at “brick-and-mortar” schools, and 1,460 in virtual school.

That’s an increase of 235 students from last year. Of those, 164 (about 70 percent) were enrolled in the district’s virtual school, a program that allows students to study and receive classroom instruction online.

The head-count enrollment translates to 9,828.9 “full-time equivalent” students in the district, an increase of 124.9 from last year.

However, in the complex world of Kansas school finance, not all students count equally for budget purposes. The state formula applies weightings for certain kinds of students, reflecting the fact that they are more costly to educate than others.

For example, each “at-risk” student — those who qualify for free lunches — counts as about 1.5 students for funding purposes. Special education students, English language learners, students enrolled in vocational education and students who have to be bused long distances also receive weightings.

With all of those factors included, the total “weighted” enrollment in Lawrence schools stood at 17,345.4 on Sept. 20 — exactly 11 more than district officials had projected when the board approved its budget in August.

Superintendent Rick Doll said the district had planned for an increase of 73 students in brick-and-mortar schools. The actual increase was 71.

Those numbers were based in part on projections provided by a consulting firm, RSP and Associates, although district officials made some adjustments to those numbers, Doll said.

He said one key adjustment involved accounting for transfers within the district. Lawrence has a relatively loose policy allowing students to transfer from the school where they would normally attend to another school of their choice, especially within elementary grades.

The estimates provided by RSP, he said, are based on where students reside. But they don’t necessarily reflect where the students will actually attend.

In other business, the board:

• Authorized refinancing up to $10 million in general obligation bonds that were issued in 2006 to obtain a lower interest rate, resulting in a net savings of $1 million to $1.4 million.

• Approved a contract with RSP and Associates to perform another enrollment projection, with a base contract amount of $15,000 and optional add-ons that could bring it to a maximum of $25,500.

• Authorized the purchase of consumable Math Expressions products for grades K-5.