The new, decade long study conducted by the Kennedy Krieger Institute and published Friday in the Child Developmentjournal, finds that having a poor “gut sense” of numbers can lead to dyscalculia. An inaccurate number sense is just one cause of math learning disabilities, according to the study led by Dr. Michele Mazzocco of the Baltimore institute.
Mazzocco -- also a psychiatry and behavioral sciences and education professor at the Johns Hopkins School of Medicine -- tracked 249 kindergarteners in Baltimore public schools in 1997. Johns Hopkins colleagues Lisa Feigenson and Justin P. Halberda later joined the project.
The team followed the Baltimore students’ math performance through 9th grade and, from grades 6 to 9, tested specific math-related abilities, such as timed computation and decomposition -- i.e. the ability to deduce which numbers in a group add up to a target number. The researchers also assessed students’ general cognitive skills, such as working memory, visual perception and symbol decoding.
When the students hit the 9th grade, the researchers conducted two experiments designed to gauge their mastery of foundational mathematical thinking, namely the “approximate number system," which refers to a person’s ability to understand a number’s magnitude, to see a group of items and estimate how many there are, or simply deduce that one group has more than another.
“Right away, early in the school-age years, it was apparent anecdotally that some of the children had real difficulty with that [estimation] number sense -- but not all of them,” Mazzocco said to Education Week.
The new experiments asked a representative 71 Baltimore students to complete a number naming and number discrimination task. The researchers then compared the performance of four groups: average math students, high-performers in the top 10 percent, students performing in the bottom 10 percent to 25 percent, and, finally, the bottom 10 percent, identified as having dyscalculia.
Mazzocco found students with dyscalculia were significantly worse at estimating than other students, with precision levels of a toddler or preschooler.
Her findings are in line with an emerging body of research in neuroscience and cognitive science.
Although math-learning disability affects about 5 percent to 8 percent of school-age children nationwide -- about as many affected by dyslexia -- research on the reading disability has for decades stunted studies of math disabilities by 20 to 1, say experts.
The recent spotlight on U.S. competitiveness in the STEM subject areas may help account for the new interest in math learning disabilities.
“Historically, there just hasn’t been as much focus in society on math difficulties as in reading,” Mazzocco said. “It’s exciting that it’s shifting a bit.”
The Kennedy Krieger Institute's findings -- which reveal that a weak sense of numbers is not the only potential source of math difficulties -- reinforce that a "one size fits all" approach to education may not be adequate for children who struggle with math.
“A key message for parents and teachers is that children vary in the precision of their intuitive sense of numbers. We might take for granted that every child perceives numbers with roughly comparable precision, but this assumption would be false. Some students may need more practice, or different kinds of practice, to develop this number sense,” said Mazzocco in an announcement.
“At the same time, if a child is struggling with mathematics at school, we should not assume that the child’s difficulty is tied to a poor number sense; this is just one possibility.”