The Washington Post reports this week on a math error by the state taxation department, which overstated the wealth in Montgomery County by $16 billion. Because state aid to schools is based on local wealth, that meant that Montgomery County schools were deprived of $24 million in state money to which they were entitled this year. And 17 other school districts got more money than they were supposed to, resulting in overpayments of $31 million.

 That's a pretty big mistake any year, but particularly in this economic climate. Gov. Martin O'Malley has promised to repay Montgomery schools and not to take away from the systems that got extra money.

And then, The Post reports, MSDE got state figures on which to calculate aid for next fiscal year. This time, Montgomery appeared less wealthy than the rest of the state and would be due to receive most of the state's new funds while other districts were short-changed.