Here are a few guidelines for determining how to write numbers as numerals or words.
1. When a number begins a sentence, it is usually written out as words:
Four thousand people applied for ten places in the program.
2. When a number is used as part of a legal or commercial document, use both numerals and words:
Client agrees to pay fifty-five dollars ($55.00) per hour for professional services outlined in this Contract.
3. Use figures when the numerical information takes more than two words to explain:
At $11.25 an hour it would take at least three years to save enough money to pay off the debt.
Thanksgiving Day is the fourth Thursday in November; last year Thanksgiving Day was November 23, 2006.
4. Time of day, addresses and identifying information all have systematic number/word formats:
10:00 AM - or - ten o’clock in the morning
11:30 PM - or - half-past eleven at night
241 Elizabeth Street, New York, NY 10012
Interstate 84 North
WLIW-TV Channel 21
5. Books, plays and musical divisions:
Chapter 4, page 13
Act II, Scene iv
Beethoven’s Symphony No. 9 in D minor, Op. 125
6. Large numbers:
11.5 million people
$4 billion - or four billion dollars
7. Decimals and fractions:
Carol maintains a 3.6 grade point average.
Add 3/4 cup of sugar to the mixture.
Three percent of the group finished the assignment.
8. Statistics and numbers in series must be consistent:
We added six bananas, two pears and three mangoes to the fruit salad.
We added 6 bananas, 2 pears and 3 mangoes to the fruit salad.
The room measured 10 feet by 12 feet.
The room measured 10′ x 12′.
9. When in doubt, clarity takes priority:
This month six 50-year-olds joined AARP. (This is easier to read)
This month 6 50-year-olds joined AARP. (This could be confusing 650 year olds?)
10. Pluralizing numerals:
The group broke up into committees of 3s and 4s to study the matter.
In the 1960s people bought record albums to listen to music.