Bad at math? It’ s your dyscalculia
SAN JOSE, Calif. — Can’t calculate a tip or even balance your checkbook?
Take heart; maybe you can blame your brain — specifically, the parietal cortex in the top back part of the head. And it could be a problem that has roots not in a failed arithmetic or “new math”lesson, but even earlier.
Recent findings indicate that how well 3-year-olds estimate quantities predicts their math ability in elementary school. Another study funded by the National Institutes of Health shows that the innate capacity to estimate is impaired in children who have a math learning disability.
The findings are so new that there’s no widely accepted way to diagnose what’s known as dyscalculia, nor any set strategies for coping with it — even though 5 to 8 percent of the population is thought to suffer from the math learning disability. Consider it the mathematical partner to dyslexia, which impairs reading ability.
But while researchers have explored causes of dyslexia and developed strategies for compensating, the study of dyscalculia lags about 30 years behind. As a result, many people remain stymied by math.
“Children are being considered lazy or unmotivated, or not to have potential, when in fact they have a disability in processing numbers,” said Michele M.M. Mazzocco, the lead researcher on the studies. “We need to learn how this can be overcome.”
Mazzocco and colleagues at the Kennedy Krieger Institute in Baltimore began tracking 249 kindergartners in public schools in 1997. She found large differences in children’s estimation skills. Even as ninth-graders, some who viewed a set of colored dots flashed briefly on a screen found it difficult to consistently estimate the number, or to distinguish quantities, such as 20 dots from 15 dots.
To tell how many dots we see or to compare quantities, the brain taps into its “approximate number system.” Mazzocco found that students in the bottom 10 percent of math achievement lagged in those estimation skills. But that doesn’t apply to everyone who “doesn’t get” math; the study found that children in the bottom 11 to 25 percent had no problem with estimation.
What dyscalculic children lack is “number sense,” something that most people take for granted but is a construct that can’t always be taught.
The ability to estimate is an oft-tapped skill that, for example, helps waiting shoppers determine which checkout line is likely to move faster at the grocery store.
“You can’t just tell somebody that 8 is more than 4,” Mazzocco said. “It’s not like memorizing states and their capitals.”
Just like dyslexics, children suffering from dyscalculia may be intelligent, she said. “They are processing information differently.”
Sharon Noguchi The Columbus Dispatch