# Should I use letters or digits in the following case?

De-Shi was holding something that looked like a price tag. It had the numbers 024 written on it.

"Isn't that what cows wear as earrings?"

"Yeah," De-Shi said, still inspecting the object, a thoughtful expression on his face, "an ear tags."

I knelt down next to De-Shi. “024. I think it belonged to the cow number 24. You know, from the 30 that jumped.”

“It’s possible.”

Right now I'm only using digits. Should I change some of them to letters? (I always get confused about this. Is there a general rule that tells you when to use letters and when to use digits?)

• Personally, I'd go for "024" and "cow number 24", but "from the thirty". When you give a number (a set of digits), keep it a number, but if you give a count of something, say that count.
– SF.
Dec 10, 2014 at 16:18

I'd do:

De-Shi was holding something that looked like a price tag. It had the numbers "024" written on it.

(1) quote any text, no matter if it was spoken or found written somewhere
(2) if you don't quote the numbers, 024 is one number (not plural), so either 'the numbers "024"' (read: oh-two-four) or 'the number 024' (read: twentyfour)

"Isn't that what cows wear as earrings?"

"Yeah," De-Shi said, still inspecting the object, a thoughtful expression on his face. "An ear tag."

(3) "tag", not "tags"
(4) I would also split that sentence: '... face. "An ...'

I knelt down next to De-Shi. “Twentyfor. I think it belonged to cow number twentyfour. You know, from the thirty that jumped.”

(5) or: "Zero two four. I think it belonged to cow number twentyfour. ..."

“It’s possible.”

• Thanks for the edits. So, in the last example you did it because it's incorrect to use digits in dialogue? And one last question: why twentyfor instead of twenty-four?
– wyc
Dec 10, 2014 at 12:53
• Not incorrect, no, but not good style. We think of letters as representing sounds of the spoken language. But we do not think of the number symbols as something we can hear, rather they represent an abstract idea. When I read "24" in a literary text, I think of these numbers being written somewhere, not being spoken. So if someone says the word "twentyfour", I would write that word, not the symbol for the numerical concept. I leave "024" in the first line only because you have that leading zero. If that was not there, I would use "twentyfour" even outside the dialogue.
– user5645
Dec 10, 2014 at 13:02
• I know the common rule says to represent numbers larger than 20 as numbers, but I write out all short number words nevertheless. It looks better to write that "a thousand men advanced on the castle" than "1000 men advanced on the castle".
– user5645
Dec 10, 2014 at 13:03

My general rules, adapted from AP style:

• In narrative prose, use digits for 10 through 99.
• Use digits for 100 and above unless the number can be expressed in two words (like two thousand or five hundred or a hundred million).
• In dialogue, write out all numbers. You don't say "47," you say "forty-seven," as @what points out.
• Write out digits under 10 in prose and dialogue.
• Just so I don't misunderstand this: you write "20", but "five hundred"? That doesn't seem to make sense.
– user5645
Dec 10, 2014 at 20:38
• @what Hmm, you make a good point. I would write out "five hundred" because it looks tidy in two words, but I wouldn't mark "500" as wrong in prose. It's a personal style, not a hard-and-fast rule I can cite. Looking up AP, I thought that was their rule, but apparently it isn't. Dec 10, 2014 at 21:42