Arithmetic – aka mental calculation – is the ability to perform mathematical operations on quantifiable concepts. Although arithmetic requires less mental effort than memory or attention processes, it's still important – most of us use it on a daily basis. Accountants and cashiers use it to earn a living; homeowners need it to pay their bills, and it's useful to shoppers to verify the change following a purchase. You use arithmetic to predict what time you'll be getting home when it's 2:25 p.m., you have 160 miles left to go and you're traveling at 60 miles per hour (for the answer, see below).
Even though your ability to do math is an important part of your daily life, this brain function isn't yet fully understood. But scientists have managed to figure out several things. Recent MRI experiments have led to the discovery that you have an "independent" brain function that processes arithmetic and is not specific to any of your senses. Regardless of whether the mental calculation problem is presented to you visually (a written equation), or verbally, you use similar parts of your brain to solve it.
Other recent discoveries suggest that your brain uses different processes to solve math problems depending on whether they require exact or approximate answers. Exact arithmetic, -- say, solving "57 + 75" -- requires that the areas in your brain located near the language centers be functioning properly. This is because you have to learn (usually at school) the mathematical language needed to solve this equation.
On the other hand, approximate arithmetic, such as the ability to calculate whether 26 + 32 is closer to 60 or 75, is not processed in the same manner or in the same part of your brain.
Researchers have discovered that this type of arithmetic is more the result of an innate type of “numerical sense.” They have demonstrated that young children and even certain animals, such as monkeys or rats, that obviously never learned the mathematical language, are able to solve certain approximate math problems. Your brain can use this "numerical sense," located in an area of the parietal cortex located in the upper part of the brain, to perform rough calculations, and, in conjunction with other cognitive functions (such as working memory), to solve more advanced problems and even produce highly complex mathematical thoughts.
Arithmetic and Automatic Responses
You were taught the addition and multiplication tables at an early age (2 + 2 = 4, 5 x 5 = 25, and so forth), and learned to respond automatically so that they require very few cognitive resources to solve. So your brain no longer processes them with its "numerical sense." In fact, these operations are so common for you that they're stored in your long-term memory, and the answers come to you automatically without the need to calculate. In these cases, your brain has cleverly found a way to avoid having to expend any effort to calculate.
Arithmetic and Working Memory
Working memory is the function that actively maintains information in memory long enough for you to do something with it. It's not necessarily specific to digits and numbers, but it is often associated with arithmetic in many everyday situations involving mental calculations.
For example, when a math problem involves a series of operations and/or an equation involves several numbers such as 12 + 76 - 21, you use your working memory to calculate the first addition and then subtract the third number from that sum. Your prefrontal cortex, located at the front of your brain, must be functioning properly for your working memory to solve arithmetic problems like these.
P.S.: The answer to the problem above: you'll reach your destination at 5:05 p.m. |
