In addition to being easier to scan for, numerals take up less space than numbers spelled out using letters—a copywriter's dream! Here are a few tips to incorporate them into your UX writing and make your copy that much more effective

1. Use numerals for all numbers, regardless of whether the number is big or small. Most writing style guides dictate that numbers lower than 10 should be spelled out (eg, "eight" instead of "8"). While that may make sense for a white paper, ditch that rule on the web, especially in places like error messages. Users scan for things they're looking for or that jump out at them. Numerals do that; letters don't. BAD: Only one left in stock GOOD: Only 1 left in stock
   

2. When percentages exceed 100%, avoid them like the plague. Most people don't know what they mean. Use "times" or the "X" multiplier instead. BAD: Revenue increased 300% BETTER: Revenue increased 4 times BEST: Revenue increased 4X (I haven't tested this hypothesis yet, but I suspect that if you ask people what a 200% increase in pay means, most will respond that their salary doubled. But in fact, it tripled.)
   

3. On its surface, this one appears to contradict Tip #1, though not really: When writing out times that are noon or midnight, don't use expressions like 12:00 PM or 12:00 AM—just use the words "noon" and "midnight" instead. They require less thinking by the user, which is always a good thing. BAD: 12:00 AM GOOD: Midnight This is a rare example when words are easier to comprehend than numbers.
   

4. And while we're on the subject of times, avoid using time zone abbreviations like "EST" and/or "EDT" to distinguish between standard and daylight savings time. Doing so only opens you up to potentially having to switch your copy between the two every 6 months. The juice ain't worth the squeeze here. Does it make a difference to the average reader? Doubtful. Instead, just sidestep this whole can of worms. BAD: Opens at 3 PM CDT BETTER: Opens at 3 PM CT BEST: Opens at 3 PM Central

Any others that I failed to neglect? If so, drop me a note at vikram@ghostmile.com or speak with my chatbot in the lower right corner. He's starved for attention!