Who knew? Who knew that Orange is being shortchanged by about $3.5 million by the state’s school aid formula? The town’s taxpayers may not have known, but they sure are feeling the pain, the absence of that extra money – which represents about a sixth of total town spending.

In recent years, rural schools and towns have been making lots of noise – and getting some attention and relief from Boston lawmakers – about an imbalance in state school aid between rural schools and urban ones.

But Orange and other communities scattered around the state are suffering from another imbalance caused by the state’s flawed 25-year-old school aid formula that wildly underestimates high special education costs.

The special education issue is costing Orange taxpayers about $3.5 million a year, town officials calculate. That’s huge in a town with a total budget of about $20 million.

According to Finance Committee member Kathy Reinig, the school aid formula uses an “assumed percentage” to calculate how much districts should get for special education reimbursement. The state calculates the number of in-district special education students in a nonvocational environment — like Orange’s elementary schools — as 3.75 percent of total enrollment, rather than polling the districts and finding out how many in-district special education students they actually have.

“The formula says 3.75 percent, but in Orange there is 159 of 613 students (in this special education category) or 25.94 percent,” Reinig told the Recorder.

The Chapter 70 formula calculates, or “assumes,” Orange has 22 in-district special education students out of its total 613 elementary school students. That costs the town taxpayers money that could be spent elsewhere in the schools or for other municipal services.

“(There is a) significant difference that this would have on the town even if we got just a fraction of this $3.5 million difference,” Reinig said.

Last year, for example, Orange’s schools saw some cuts to services, including the elimination of a kindergarten class at Fisher Hill School, which has contributed to so much political and educational turmoil there.

The town Finance Committee has written a letter about special education to the governor, penned by Reinig, asking that the state use the actual number of special education students in each district, rather than an assumed number, in a new state aid funding formula. The current formula uses the real number of English language-learning students, known as ELL students, so it should do the same for special education, she contends.

We agree, and we would urge every city and town to advocate for the change whether it affects them or not. This is a question of fairness.

Orange may also attempt to forge a coalition of towns in the same boat, which we also encourage, because there is strength in numbers, and in this case, a compellling case in the data.

Reinig said she will be having meetings, on behalf of the Finance Committee, with state Sen. Jo Comerford, D-Northampton, to address the issue. Our local lawmakers on Beacon Hill don’t usually have to be encouraged to advocate for us, so we probably don’t need to urge them to support Orange in this case, but they might want to reach out to fellow legislators of similarly affected communities, to build a legislative coalition for this change just as Orange tried to build a lobby of cities and towns.