If you want your audience to remember and share specific numbers, statistics and data points in your presentation, you're probably designing your slides all wrong. Overwhelming your audience with multiple charts, graphs, and words on one slide is the single worst way to deliver information, according to neuroscience.

The most effective way is the Apple approach. On Tuesday, Apple launched new products--including a new Macbook Air and iPad--at a press event in the Brooklyn Academy of Music. During the presentation, Apple CEO Tim Cook delivered some numbers he wanted everyone to know about. Many of the journalists and bloggers in the room ended up using the same statistic in their headlines: 100 million.

  • "Apple hits 100 million active Macs" (Forbes)
  • "There are now 100 million Macs in use" (TechCrunch)
  • "Apple says there are 100 million Macs out in the wild" (CNET)

Why are these headlines calling attention to the same number? It's the way Apple wants it. Apple's presentation designers are experts at creating memorable and shareable messages--especially statistics.

The strategy is so effective that you shouldn't give another presentation without incorporating it. Here's the trick.

Stick to one number per slide and build up to it. 

Tim Cook didn't bury the statistic in the middle of a slide with other numbers on it. He built up to it, his voice starting soft and growing louder, before dropping it on the audience:

"The Mac continues to attract many new customers. In fact, over half of Mac buyers worldwide are new to Mac. We're adding millions and millions of new customers every quarter, bringing our total active installed base to a new major milestone--of 100 million Macs!"

Right on cue, the statistic "100 million" drops into the slide with animation to make it look like it's kicking up dust upon landing. It's that big a number that it figuratively lands with a thud. The font size took up the nearly the entire length of the slide. 

The human brain cannot absorb too many pieces of information at once. Give your audience too many numbers to remember at once and they're unlikely to remember any of them.

Apple speakers apply this rule to product specs, too. If you look up articles or reviews about the new Macbook Air, you'll likely find this statistic in nearly every one: 10 percent thinner. That, too, is on purpose.

When Apple executive Laura Legros introduced the new laptop on stage, she showed a slide with one image: the new computer side-by-side with the previous version. "It's incredibly thin. It's just 15.6 millimeters," she said.

That was the build-up. Next, she said: "That's 10 percent thinner than the previous air." 

In one photo and one statistic, you get the big picture. 

Some of the best professional designers in the business have told me that slides should be simple enough to get the key message across in about 2-3 seconds. That leaves very little room for too many words.

It's why the one message per slide rule works well. If you want people to remember one number, make it the only number on the screen. If you want your audience to associate the statistic with a product or company, attach the number to a photo. But that's it. 

One number per slide. It's a proven tip that will make your message instantly memorable.