Writing Numbers
Psaní číslovek

Although usage varies, most people spell out numbers that can be expressed in one or two words and use figures for other numbers:

Words
over two pounds
six million dollars
after thirty-one years
eighty-three people

Figures
after 126 days
only $31.50
6,381 bushels
4.78 liters

Here are some examples of specific situations.

Days and Years
December 12, 1965 or 12 December 1965
A.D. 1066
in 1900
in 1971-72 or in 1971-1972
the eighties, the twentieth century
the 1980's or the 1980s

Time of Day
8:00 A.M. (or) a.m. (or) eight o'clock in the morning
4:30 P.M. (or) p.m. (or) half-past four in the afternoon

Addresses
16 Tenth Street
350 West 114 Street

Identification Numbers
Room 8
Channel 18
Interstate 65
Henry VIII

Page and Division of Books and Plays
page 30
chapter 6
in act 3, scene 2 (or) in Act III, Scene ii

Decimals and Percentages
a 2.7 average
13 1/4 percent
.037 metric ton

Large Round Numbers
four billion dollars (or) $4 billion
16,500,000 (or) 16.5 million
Notes on Usage

Repeat numbers in legal or commercial writing.
The bill will not exceed one hundred (100) dollars.

Numbers in series and statistics should be consistent.
two apples, six oranges, and three bananas
NOT: two apples, 6 oranges, and 3 bananas
115 feet by 90 feet (or) 115' x 90'
scores of 25-6 (or) scores of 25 to 6
The vote was 9 in favor and 5 opposed

Write out numbers beginning sentences.
Six percent of the group failed.
NOT: 6% of the group failed.

Use a combination of figures and words for numbers when such a combination will keep your writing clear.
Unclear: The club celebrated the birthdays of 6 90-year-olds who were born in the city. (may cause the reader to read '690' as one number.)
Clearer: The club celebrated the birthdays of six 90-year-olds who were born in the city.