It's an exhibit thousands have passed by over the years. "Mathematica," at the Museum of Science in Boston, tells the history of math. But it turns out part of the story is wrong, and no one noticed until decades later, when a tourist from Virginia realized the exhibit's "golden ratio" was written incorrectly.

At 15, you can already call Joseph Rosenfeld a "numbers guy," which is why the series of math equations at the exhibit was of particular interest to him.

"You can like skim through it and not really go in depth on any of them, or you can cut out a couple and go in-depth on some. And I wanted to read the whole plaque," he said.

So he did.

According to My Fox Boston, Joseph began to read a plaque that featured what he calls a pretty famous equation-- "the golden ratio."  But as he read it, he realized something was wrong.

"There was a minus sign instead of a plus sign three times when it quoted the equation for the golden ratio," he said.

Amazingly, the exhibit has been in place since 1981, and no one has ever noticed the mistake.
  
Not the experts. Not the museum staff. Not the thousands of people who have visited the museum.
    
No one, until Joseph. He's got a theory as to why that is.

"They had the text big but the equation small, so I guess it's pretty easy for your eyes to skim over," he said. "That exhibit is pretty cluttered. Most people probably didn't have time to read the whole plaque for the golden ratio."

Joseph told the museum, and after taking a look, they emailed him to tell him he was right.
    
His dad says he believes the museum has fixed the issue.
    
Joseph says -- unsurprisingly -- he'd like to be an engineer one day, maybe ending up at MIT.