There are heaps and heaps of rules on the use of numbers in fiction, for example:

1. Write out numbers one to one hundred; 101 and above, use numerals.

So, this:
CORRECT: Published in thirty-eight languages, Barbara Cartland wrote 723 novels.  

But then, there are exceptions to Rule Number 1:

2. When a sentence begins with a number, always spell out the word.

3. Round numbers should be spelled out.

INCORRECT: 501 books were written by Isaac Asimov, and he wrote over 90,000 letters. 
CORRECT: Five hundred and one books were written by Isaac Asimov, and he wrote over ninety thousand letters.
Also CORRECT: Writing 501 books didn’t stop him from sending 900,001 letters.

Got it? I hope so because that was an easy one. The more I ponder various number usages, the more mind-boggling it becomes. It gets downright weedy.  


This, from a hot-blooded discussion on the discussion board of the writers’ cult favorite, the Chicago Manual of Style:

“Numerals that are usually numerals (such as phone numbers, seat numbers, odd dollar amounts, and so forth) seem to scream to stay that way. In my opinion, spelling them seems to add a layer of awkwardness and unnaturalness.”

Maybe so, but the Chicago Manual of Style maintains that people speak in words, not numbers.

So, this:
CORRECT: “Quick! Dial nine-one-one! I spent three hundred twelve dollars and fifty cents at the bookstore on ninety-two Stephen King titles. Thirty-five minutes later, when getting on the Seventeen A bus, I threw out my back.”

Sometimes prose rhythm or a stylistic choice may dictate breaking the rules. Writer’s Digest actually follows the AP Stylebook, with some modifications. AP is designed for space saving in newspaper/magazine column inches and thus opts for numerals in some scenarios, simply to save on the number of characters rather than for aesthetic reasons. 

Above all, stay consistent throughout your book. 

I’ve got your number

The rules in this post address a few common “number mistakes”—those I often come across when editing fiction manuscripts. Here’s a place to start:

13 times in the 1530’s, Henry VIII phoned and said, “Pope Paul III, pay me the $50 you owe me, or there will be 125% interest.”

Okay, that sentence is a mess. When fixing it up, numerous rules apply. You should know the first; you were tipped off above. (Rule #2: When a sentence begins with a number, spell out the word.) Other pertinent rules:

4. For decades, an apostrophe need not be added. (30s, 1930s—not 30’s, 1930’s)

5. Roman numerals may be used in personal names, but not in dialogue.

6. In dialogue, spell out numbers.

7. Symbols ($,%) should be replaced with words in dialogue and text.

Crafting prose is different from writing a recipe or bank statement or itinerary. Cleaned up, the sentence should read:

Thirteen times in the 1530s, Henry VIII phoned and said, “Pope Paul the Third, pay me the fifty dollars you owe me, or there will be one hundred twenty-five percent interest.”

Second chances

8. When using ordinal numbers (3rd, 25th, et cetera), follow the same one-to-ninety-nine spelling-out rule.

She was a fourth grade nothing.
Langston Hughes lived on East 127th Street.

9. When marking ordinal numbers, use normal-sized type, not super-script: 112th, not 112th.

Make a date

Speaking of -th’s:

10. Ordinal numbers should not be used for dates that include the month, or the month and year.

INCORRECT: Sherlock was born January 6th.
CORRECT: Sherlock was born January 6.
INCORRECT: Sherlock was born January 6th, 1854.
CORRECT: Sherlock was born January 6, 1854.

Even if the suffix -th is not on the page, the ordinal may be pronounced by (or in the head of) the reader. In other words, you might read it like the first example above, but you write it like the second.

Tick tock

Sometimes logic plays a dubious role in the rules. For example, how would you punctuate a.m./p.m. at a sentence’s end?

INCORRECT: Professor Robert Langdon arrived at the Louvre at 3:23 p.m..
CORRECT: Professor Robert Langdon arrived at the Louvre at 3:23 p.m.

11. Do not use a period when ending a sentence with a.m. or p.m.

And a few other timely rules:

12. Use numerals to call attention to an exact time or when including a.m. or p.m.

It was 4:44 a.m. when Edgar Allan Poe finally felt inspiration.

13. Spell out the number when using o’clock.

Dorothy Parker thought it was five o’clock somewhere.  

In the Heights

Remember that ban on symbols. Even when describing technical details, you’re still writing prose:

INCORRECT: Harry Potter was 5’ 11”.
CORRECT: Harry Potter was five foot eleven.

You can correctly write a character’s height a number of ways:
He was five feet eleven inches tall.
He was five feet eleven.
He was five foot eleven.
He was five eleven.

The gun on the mantle

For so many reasons, it gets dicey when your character aims a gun.

14. Include the numbers and letters of guns and military hardware. Capitalize the brand and manufacturer, if used. Spell it like their makers spell it.

Team Yankee had ten M1 Abrams tanks, five M113 armored personnel carriers, and two TOW missile vehicles.

Remember the spell-out-numbers rule?  These complicated spelled-out numbers can look weird to readers, so some thriller writers balk at that rule and make their own style choices. (Your future publisher, however, may have a different style sheet.)

Military thriller writer Brian Andrews says he avoids putting technical details in dialogue and sneaks them into explanatory prose to avoid unnecessary reader confusion. Still, others flaunt the dialogue-spelling-out rule and include numbers in the dialogue:

CORRECT: Jack Reacher said, “That’s a Glock Seventeen.”
PREFERRED: “That’s a Glock 17.”

More rules, more exceptions

When questions or controversies arise, the Chicago Manual of Style is highly recommended. And while different standards may be chosen, all choices should be consciously made.

To repeat: consistency is key.

Of course, you want to make your manuscripts as readable and flawless as possible. Even so, career authors hope to be lucky enough to have their publisher assign their book to the meanest, most persnickety copyeditor. Such a person is a novelist’s difficult best friend.


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