Editor's note: This story clarifies numbers used in earlier reporting.

North Stonington — Stonington officials used incorrect numbers in preparing a draft of a study to entice the town of North Stonington to send students to Stonington High School.

Released on March 10, the study included a number of benefits for North Stonington high school students at Stonington High School, including additional classes and sports available.

It did not include the financial information, though it noted that there would be "financial benefits to both towns" under the arrangement.

However, internal documents obtained under the Freedom of Information Act show that as Stonington officials prepared and later deleted a section arguing North Stonington would benefit from sending its high school students to Stonington High School, they were using incorrect data.

The data came from a 2013 state spreadsheet titled "Elementary/Middle and Secondary per Pupil Expenditures," which reports the amount of money high schools and elementary schools spend per student across the state.

Most schools report this information in two groups: kindergarten through eighth grade, and ninth through 12th grade.

Because of the shared resources in Wheeler Middle High School, Business Manager Kimberly Allen said, North Stonington reports its numbers as pre-kindergarten through fifth grade and sixth grade through 12th grade.

The state spreadsheet used by Stonington accounts for some schools that calculate those numbers differently, but North Stonington's expenditures were incorrectly recorded as kindergarten through fifth grade and ninth through 12th grade.

This means that the entire spending of both the middle and high schools was divided by the relatively small enrollment at the high school, resulting in higher, inaccurate numbers for the high school's operating costs and per-pupil expenditures.

It was not immediately clear why this occurred, though Allen said the district had been reporting the high school enrollment information and would in the future correct it to match the way expenditures are submitted.

Stonington officials used the incorrect figure on the state website to calculate a potential savings in their draft of the feasibility study by comparing that expenditure with the per-pupil expenditure at Stonington High School.

Because North Stonington's numbers are calculated differently from Stonington's, Allen said, it is inaccurate to compare them.

She pointed to the net current spending per pupil across all grades in the district, an audited figure from the state that for North Stonington was $15,462 in the 2014-15 academic year, as the best way to compare the districts' per-pupil expenditures.

Allen said for as long as she had worked in the North Stonington school district, its numbers have been reported as pre-kindergarten through fifth grade and sixth through 12th grade.

"At the middle/high school, they share transportation, the cafeteria, nursing, guidance and all of the administration and secretarial staff are shared. That's why we report it out as one building," Allen said.

In the future, the state will be putting out a uniform chart of accounts to allow for direct comparisons with other schools, Allen said, and the business office in North Stonington is preparing to convert to that system.

Using the actual enrollment that matches the reports in 2013, the per-pupil expenditures from the elementary school would be $16,113, and the per-pupil expenditures at the Middle/High School would be $15,881.

Allen said these numbers were more accurate, though since they are not audited she prefers using the net-current expenditure.

Stonington Superintendent Van Riley, in an interview, said he didn't know that the data reflected the way North Stonington reports its expenditures when he included it in his draft, and said he hadn't looked at the data since it was removed.

In an interview last week, Riley said he felt the state information was clear and the best way to compare the schools, though he was unsure whether North Stonington had reported the information correctly.

In another interview last week, Board of Education Chairman Frank Todisco said the financial piece was eliminated because "(it) should be reviewed with the board in a formal presentation."

Both Riley and Todisco later wrote a letter noting they would not pursue the study further without the support of North Stonington.

n.lynch@theday.com