Chances are you’ve heard of the reading disability dyslexia. It reportedly affects up to 15 percent of the population, and public figures from the fictional Jaime Lannister in HBO’s Game of Thrones to real-life comic Eddie Izzard have grappled with the learning disorder. But have you ever heard of dyscalculia, the math disability? Probably not, even though up to six percent of elementary school students in the U.S. may struggle with it.

A big part of the general population's unfamiliarity with dyscalculia has to do with our culture’s general discomfort with numbers, and our ingrained belief that math—compared to reading—is just supposed to be hard. Dr. Gavin Price, an assistant professor at Vanderbilt University who has researched dyscalculia in several countries, says, "When I teach classes, I’ll ask at the beginning, 'How many people think they’re not good at math, they’re bad at math?' And half of them put their hands up. Then I ask, 'Are any of you bad at reading?' And nobody puts their hand up."

Dr. Edward Hubbard, an assistant professor at the University of Wisconsin-Madison, echoes this sentiment, and adds that attitudes toward math may play a part not just in our overall lack of dyscalculia awareness, but in the fact that dyscalculia research is at least two decades behind dyslexia research.

“I think some of it is cultural attitudes towards math,” says Hubbard, who has researched dyscalculia in France and the United States and heads up his university’s Educational Neuroscience lab, which is embarking on a new dyscalculia study. “If you look around, the number of people who sort of say, 'I’m bad at math,' and laugh about it, or will say, without batting an eye, 'I’m just not a math person,' is striking.”

So, in the interest of raising dyscalculia awareness, begin your crash course on the little-known mathematical disorder with these 11 facts.

1. The term dyscalculia was coined in the 1940s, but didn’t really become fully recognized until the 1974 work of Czechoslovakian researcher Ladislav Kosc.

Kosc defined the disorder as "a structural disorder of mathematical abilities" caused by impairment to the parts of the brain used in mathematical calculations, without simultaneous impairment to one's general mental abilities. (In layman's terms: You're bad at math because parts of your brain aren't working properly, but you're not otherwise mentally handicapped.) Today, some research communities also use the terms “math dyslexia” and “math learning disability” to refer to the condition.

2. There are two types of dyscalculia.

Most people diagnosed with the disorder have developmental dyscalculia, which means they were born with it. But, with what's known as acquired dyscalculia, the disorder can also arise later in life, usually as the result of a stroke or injury.

3. Struggling with matrices in algebra or flunking calculus in college doesn’t usually mean you have dyscalculia.

This disability tends to impede your most basic skills. “Somebody who has dyscalculia will struggle with the most basic arithmetic facts, 5+2=7,” Hubbard says. “They will struggle to tell you seven is larger than five. We’ll see them counting on their fingers for basic addition.”

4. Dyscalculia may be rooted in the brain's parietal lobe.

What causes dyscalculia? To date, the most popular theory maintains that dyscalculia is connected to an inability to judge quantities, a sense that is concentrated in the parietal lobe.

“One of the theories that exists is that dyscalculia is really caused by an impairment in what’s known as either the number sense or the approximate number system,” Price says. “And that system is what allows us to know that, for example, a group of five apples is more than three apples. It allows us to compare, and order, and process quantities without the use of verbal symbols or labels."

"And so what we did [in a study in Finland]," Price continues, "was scan these dyscalculic kids while they were doing those type of tasks, and we compared their brain activation to the typically developing kids, and we found that indeed this region in the parietal cortex, the intraparietal sulcus, behaved atypically in these kids when they were processing these non-symbolic numerical magnitudes.”

5. Researchers have been able to induce dyscalculia in patients.

In 2007, a group of researchers at University College London were able to engender temporary dyscalculia in people who don’t have the disorder by using transcranial magnetic stimulation, or TMS. TMS is often used to treat depression, and involves placing a large electromagnetic coil against the scalp.

In the study, researchers applied TMS to the right parietal lobe while their subjects were comparing quantities, and found that the stimulation briefly made it hard for the subject to tell if one quantity was bigger than the other.

6. Dyscalculia may manifest itself in different ways. 

While the above research shows that dyscalculia is closely associated with problems in the parietal lobe that affect one's understanding of the number system, researchers like Hubbard think some people who suffer from dyscalculia might feel the disorder differently.

“The problem may not be with number sense itself, but with linking number symbols with number sense,” Hubbard says. “Maybe it differs across other people. Maybe there is a subgroup of people for whom their difficulties are in the number system itself, for other people it’s in symbols.” 

7. Dyscalculia is represented in pop culture.

While dyslexic characters are much more common in popular culture, there are some examples of dyscalculics to be found. Fans of Canadian teen drama Degrassi: The Next Generation may remember Liberty Van Zandt having it, and X-Men fans may know that Wolverine's sidekick Jubilee is a whiz at manipulating pyrotechnics but not numbers.

8. Dyscalculia doesn't discriminate by gender.

You may have noticed that both our pop culture examples were female, but dyscalculia, at least at this juncture, does not appear to have a gender gap.

“My sense is that it’s pretty even. But at the same time, I feel like the gender ratio has been less a focus of investigation than it was for dyslexia,” Hubbard says, adding that research saying boys are more prone to dyslexia than girls is “pretty well supported.”

Hubbard is aware that this flies in the face of the (offensive) stereotype that women are worse at math than men—a generalization that seems to have little basis in fact. “What we see is that the gender differences [in mathematical ability] have gotten smaller and smaller. As we have better role models for girls in math, we’ve had greater opportunities and fewer impediments to girls being able to do well. The differences that we’re seeing are largely due to cultural differences.”

9. However, some groups are at greater risk of dyscalculia than others.

People with Turner syndrome, epilepsy, and Fragile X syndrome are more likely to have dyscalculia. You are also at greater risk for dyscalculia if you have attention deficit hyperactivity disorder (ADHD), if your mother drank during her pregnancy, or if you were born prematurely.

10. It can be tough to diagnose.

“One of the problems, one of the challenges with dyscalculia, the reason that it hasn’t gotten the same attention [as dyslexia], is that it is a highly co-morbid disorder,” Price says. “Often, people who are bad at math are bad at a number of things.”

But while a diagnosis may be difficult to come by, treating a patient's other conditions may also alleviate his or her dyscalculia. For example, one study of people with ADHD who both were and weren’t dyscalculic found that putting them on a stimulant improved their calculating ability, but not their basic numerical skills.

11. There is no cure for dyscalculia.

But don't lose hope! Dyscalculics can learn math, even if they may always struggle with parts of it because of their neurological differences. Luckily, you use more than the parietal part of your brain when doing math, Price says. “Multiple skills come under the umbrella of math, and all of these things will engage all of the lobes of the brain.”

Therefore, early detection is key in helping children cope with dyscalculia. And for adults struggling with the disorder, a shift in attitude may be the first step in overcoming the obstacles dyscalculia presents.

“When we think of struggling with reading, most adults would not think of going back and listening to the sounds of language,” Hubbard says. “Similarly, if you recognize that you’re struggling with math, your first thought isn’t probably that you should go back to trying to see how much stuff is out there, use this basic sense of number that I have, and try to link that to basic number symbol. People would probably try to work at a higher level. What you should really be doing is going back and looking at these foundational skills, things that most teachers, most parents, and most people assume we all just have.”