Apparently shareholders agree.
The company's stock price has held fairly constant, and the trading price for the preferred shares has not skyrocketed as you would expect if they were suddenly worth far more than expected.
GMX likely faces only legal and filing fees, which the law firm that made the error is expected to cover.
It could have been much worse. Simple math mistakes can lead to costly results.
In 2009, the U.S. Department of Energy mothballed a high-tech, low-emission coal power plant because a math error overestimated the cost by a half-billion dollars.
One year earlier, the Dallas Independent School District laid off 275 teachers and 40 counselors and assistant principals because a miscalculated budget led to an $84 million deficit.
And in one of the more famous recent math errors, the $125 million Mars Climate Orbiter in 2004 smashed into the red planet because engineers failed to convert its numbers from English to metric measurements.
You never know when you might need to remember the rules of multiplication and division.
But as for simplifying quadrilaterals and factoring imaginary numbers, I still haven't figured out when I'll need to know that.