Associated Press (AP) style is most often used by news and journalism writers to present consistent and clear writing to the consumer. When following AP style, numbers zero through nine are typically written in word form, while numbers 10 and above are written as cardinal numbers. Some exceptions, however, do exist.
Formatting Numbers of Location
To format numbers related to location, figures are used. Addresses, for instance, should be written using figures: 454 Cantor Drive or 3 Main St. Notice that even if the address begins with a number less than 10, it is written with a figure rather than spelled out. Numbered street names -- Fourth Avenue or 10th Street, for example -- are the exception, as these follow the traditional AP convention of spelling out numbers nine and below and using figures for numbers 10 and above. Figures are also used for zip codes and phone numbers. Longitude and latitude also follow this convention. For example, “The city of Atlanta lies at 33 degrees 45 minutes north latitude and 84 degrees 23 minutes west longitude."
Formatting Measurable Numbers
Numbers related to dimension and measurement are usually written as figures. For example, height and weight would be written as follows: he is 6-foot-2 and weighs 195 pounds. Figures are also used for dimensions. For example, “The sink hole is 16 feet wide and 30 feet deep.” Distances, on the other hand, follow the traditional convention: spell out numbers one through nine and use figures to denote numbers 10 and above. When communicating large numbers, including monetary sums, figures are preferred: $5 million; 90,000; $15; and 2 percent. Traditional comma rules with large numbers are followed with the exception of numbers that reach millions and above. In this case, the excessive zeroes are removed and replaced with the appropriate term -- "million," for example. Common fractions are written as words -- one-half and two-thirds -- while complex fractions are written as figures or converted to decimals.
Formatting Numbers of Time
Numbers related to time are usually written as figures. Ages, for example, are always written as figures: “the 20-year-old boy,” “he was in his 20s” and “the girl is 2.” The time of day -- 1 p.m. and 3:45 a.m. – also utilize figures regardless of the number. Numbers pertaining to dates – whether the day of the month or the year – are written as figures. For example, “That movie was released in 1992” and “Her birthday is June 2, 1975.” Sentences that begin with a year also follow this convention. For example, “2001 was an interesting political year.” Notice also that commas are not used in years.
Formatting Roman Numerals and Ordinal Numbers
Ordinal numbers -- first and 10th, for example -- below 10 are spelled out, while numbers 10 and above are written as figures and followed by “st,” “nd,” “rd,” or“th.” Ordinal numbers used to denote geographic or political zones, however, are the one exception. Whether above or below 10, these terms are always written using figures: 8th Ward and 2nd County District. Rather than figures, roman numerals – I, V, X, L, C, D and M – are used to denote wars and to establish a sequence of people, literature and events: World War I, Queen Elizabeth II, Act V and Super Bowl XLVIII.