Dinner is over, and the waiter is handing over the bills to everyone when the collective tension sets in... how much do we tip? Math can trigger anxiety in adults and kids, but now scientists at Oxford University have developed a way to flip a switch and turn a normal person's brain into a math machine. They found painless, electrical brain stimulation in combination with easy number exercises can significantly improve math ability.

The findings were published in the Current Biology today.

While simple calculations around the dinner table are frustrating, math illiteracy is a more serious problem for many adults and children. Nearly 6 percent of adults and one out of five kids suffer from developmental dyscalculia, a math learning disorder. Strokes and other neurodegenerative diseases can contribute to math difficulties later in life as well.

"Techniques that can assuage the decline in, or even enhance, cognitive learning and processing are thus highly sought after for both educational and therapeutic purposes," wrote the authors who were led by Dr. Roi Cohen Kadosh, an experimental psychologist at Oxford.

To test the idea that "brain zapping" could improve arithmetic, six people were hooked up to a machine called a "transcranial random noise stimulator." This device has two sponge-sized pads that press against the surface of the forehead and deliver soft, repetitive pulses of electricity into the brain.

Electric pulses were delivered to the dorsolateral prefrontal cortex (DLPFC) - a brain region implicated in calculations - while the subjects were given math drills. A control group of six people performed the math exercises without receiving brain stimulation. These short training sessions were given over five consecutive days.

Math ability was tested at the end of the training week. It was also tested six months later during a surprise quiz.

The researchers tested two types of skills: the ability to learn math operations (addition, multiplication) and the ability to remember "artificial" numbers (new symbols that represent quantities).

Learning rates were two times higher in the brain-stimulated group versus the controls. Both types of proficiencies - operations and number memory - improved with brain stimulation, whether the subjects were tested immediately after the training week or six months after the initial training session.

Improved math skills correlated with increased brain activity in the left part of DLPFC, a brain area just behind your left eyebrow. Brain activity was determined with an infrared brain scanner that measures oxygen consumption by brain cells. Although it is 2 percent of your weight, the brain accounts for 20 percent of total body oxygen consumption, which is more than any other organ.

"With just five days of cognitive training and noninvasive, painless brain stimulation, we were able to bring about long-lasting improvements in cognitive and brain functions," said Dr. Cohen Kadosh.

While brain stimulation improved math accuracy, it didn't increase the speed at which a subject did math. In other words, if they did 10 problems in 10 minutes before brain zapping, then they could do 10 problems in 10 minutes after the training week.

Stimulating a brain region that isn't thought to be involved with arithmetic had no effect

Kadosh feels that with better integration of neuroscience and education, this line of study could really help humans reach their cognitive potential in math and beyond.

"Maths is a highly complex cognitive faculty that is based on a myriad of different abilities," said Kadosh. "If we can enhance mathematics, therefore, there is a good chance that we will be able to enhance simpler cognitive functions."

Source: Snowball A, et al. Long-Term Enhancement of Brain Function and Cognition Using Cognitive Training and Brain Stimulation. Current Biology. 2013.