You may not have heard of it, but it's a skill you probably use everyday, like when choosing the shortest line at the grocery store or the toll booth with the fewest number of cars. Approximate number math, or 'guesstimating,' is the ability to instinctively estimate quantities without counting. Researchers at Duke University set out to discover whether practicing this ability would improve symbolic math skills, like addition and subtraction.
They discovered that study participants who were given approximate number training sessions did dramatically better on symbolic math tests than those who were not. Those who received training also received significantly higher scores on the math tests after the training than before.
Researchers believe that these findings could have implications in early-childhood education.
"We are conducting additional studies to try and figure out what's driving the effect, and we are particularly excited about the possibility that games designed to hone approximate number sense in preschoolers might facilitate math learning,” said postdoctoral researcher Joonkoo Park. Duke psychologist Elizabeth Brannon is the other author of the study.
During the training sessions, participants were required to add and subtract large quantities of dots without enough time to count them. They were shown three sets of dots, then asked whether the sum of the first two was greater, less than or equal to the third set. Each session got progressively harder.
"It's not about counting, it's about rough estimates," Park said.
During the math tests, participants were asked to solve as many two-digit and three-digit addition and subtraction problems as they could in ten minutes.
The strong link the researchers found between approximate number training and simple math skills led them to believe that guesstimating is an essential foundation to more advanced mathematical thinking.
"We think this might be the seeds -- the building blocks -- of mathematical thinking," Brannon said.
The findings, which were supported by a National Institutes of Health grant and a Duke neuroscience fellowship, were published in the journal Psychological Science.