A new Israeli-Canadian study looking at how the brain learns basic math could now affect the way dyscalculia is diagnosed in school-aged children.

The researchers used an everyday trip to the supermarket to understand how math abilities develop.

“If we are able to understand how the brain learns math, and how it understands the concept of numbers and more complex math concepts that shape the world we live in, we will be able to teach math in a more intuitive and enjoyable way. The current study is the first step in achieving this goal,” says Dr. Tali Leibovich from the University of Western Ontario in Canada.

The researchers – including PhD students Naama Katzin and Maayan Harel and Prof. Avishai Henik from the Psychology Department at Ben-Gurion University of the Negev – took the dilemma of choosing the best checkout line at the grocery store to prove their theory as to how the brain first learns basic math.

They say that the way people choose the line that will result in the shortest wait reveals how basic math abilities are acquired.

According to the most acceptable theory today, people are born with a “sense of numbers”, namely, with the ability to recognize different quantities, like the number of items in a shopping cart, and this ability improves with age. Early curricula in math and diagnostics tools for math-specific learning disabilities (i.e., dyscalculia) have been developed based on this theory.

However, the new paper — recently published in the journal Behavioural and Brain Sciences — challenges the prevalent “number sense” theory, and presents evidence supporting the claim that “number sense” is not innate, but is actually acquired. The key to this new theory is the relationship between number and size (area, density, perimeter, etc.).

In the paper, the researchers present evidence that when people compare quantities, like in the case of shopping carts, the decision is based not only on the number of items but also on size: the total area the items occupy, their density. Combining size and number allows us to make a faster and more efficient decision.

The researchers argue that first understanding the relationship between size and number is critical for the development of higher math abilities.

And this new theory could affect the way dyscalculia is diagnosed. Today dyscalculia can be diagnosed only in school-aged children. At this stage, however, children with dyscalculia are already lagging behind their peers.

“The new theory will allow us to develop diagnostic tools that do not require any formal math knowledge, thus allowing diagnosis and treatment of dyscalculia before school age,” says Dr. Leibovich.