Seven minutes is all it took for a cyber attack to cripple thousands of companies in 2017. That’s according to a new Symantec marketing campaign which references the NotPetya malware attack that struck thousands of companies. The ads suggest, of course, that if the world’s largest shipping and pharmaceutical companies could be taken out of service in seven minutes, a company might want to consider Symantec’s security products before it’s too late.

Symantec has a number of data points it can feature in any of its ads, many of which are big, impressive statistics. The company’s tools block 142 million threats a day, 300,000 businesses depend on Symantec for protection and 3,800 cybersecurity researchers are fighting threats every day. Why, then, does the company focus on such a small number: seven minutes?

Simply put, our cognitive system is not made to grasp large numbers. If a number is easier for us to perceive, we’re more likely to remember it. Try this: visualize three balloons. Got it? Now try to visualize what 5,000 balloons would look like. Since you’ve probably never seen 5,000 balloons at the same time, your perceptual (or visual) system finds it harder to retrieve a concrete example. You don’t deal with such large numbers in your everyday life. But small numbers come easily to mind.

Scientists believe our ancient ancestors had no need to understand incomprehensibly large numbers. “Early humans only really needed to get a basic sense of small batches of quantities, like the number of people in the clan, or how many animals might occupy a certain area,” according to one paper. In other words, we can easily visualize five items. We have no chance of visualizing billions or even millions. The trick is to break up large numbers into small batches.

For example in Northern California, where I live, the state is still recovering from the Camp fire, the most destructive wildfire in modern history. When the fire started, high winds caused it to burn 10,000 acres in 90 minutes. Since it’s hard to visualize thousands of acres or the speed at the which fire was burning, one news outlet put it in perspective by using a small number and a visual that’s easier to perceive. According to CNN, every second, the Camp fire burned the equivalent of one football field. For most people, 10,000 acres in 90 minutes is hard to comprehend. One football field a second? Now that’s fast.

Psychologists have found that small numbers come to mind more easily. In studies where people are asked to name a number between 1 and 100, the majority will choose a small number below 20. Small numbers are simply easier to retrieve and remember. The giant medical device company, Medtronic, understands this basic concept. The company’s devices and therapies are used to treat tens of millions of patients around the world every year. To put it in perspective, Medtronic’s marketing campaign focuses on “Every Second.” For example, “Every second, two people are positively impacted by our breadth of medical technologies and therapies”

Given the way our brains make sense of numbers, it makes no sense to present large data points without chunking the information into smaller batches. The larger number might sound more impressive to you, but your audience prefers the smaller one.