Use commas in numbers of four digits or more (the school received 1,244 applications), except when referring to temperatures (2200 degrees Fahrenheit) or page numbers (page 1446). If a number must start a sentence, spell it out, but it is best to recast the sentence: Six hundred students attended orientation this fall could become This fall, 600 students attended orientation. Do not use superscript on the word endings -nd, -rd, -st, and -th: a survey of 20th-century poetry; in the beginning of the 21st century.

Exceptions:

  • Act and scene numbers: Act II, Scene 3
  • Ages: Always use figures for people and animals. For inanimate objects, spell out one to nine: A six-year-old survey.
  • Building and room numbers: 1 Fifth Avenue; Music Building, Room 1002
  • Course credits: .5 credit, 1 credit, 2 credits, etc.
  • Course sequence numbers (roman numerals, used in course titles): Use I, II, III, IV, etc.
  • Dates and times: See the Dates and Times section.
  • Dimensions, measurements, weights, and proportions when they consist of two or more elements: the child weighed 10 pounds 5 ounces; the painting is 34 by 50 inches.
  • Money: Use figures only, but spell out and lowercase the word cents for amounts less than one dollar in running text (use decimals in tabular materials). In running text, do not include “.00” in dollar amounts: The $5 transcript fee is included in the total. For very large sums of money, use figures with a dollar sign; spell out million, billion, etc.: $1.8 million; between $1 and $2 billion.
  • Parts of a document: page 1, Section 3, Chapter V, Article 6
  • Percentages: Always use figures, and spell out the word percent in running text. Do not use the % sign except in charts or graphs.
  • Phrases and expressions: the eleventh hour, a million times no, a thousand reasons; the Gay Nineties, the Roaring Twenties
  • Temperatures: Use figures for all, except zero. Use words, not a minus sign, to indicate temperatures below zero: the temperature was 10 degrees below zero.
  • Sports points, scores, and times
  • Telephone and fax numbers (see the following for additional information)
  • These biblical references (proper names): the Twelve Apostles, the Ten Commandments

Use area codes for all U.S. telephone numbers, or at least once with a listing. This practice has become necessary because of the ubiquitous use of cell phones. One has flexibility in choosing styles for telephone numbers, as long as consistency is maintained within the document:

(607) 258-3000 or 609-258-3000 or 609.258.3000 or 609 258 3000
For 800 numbers: (800) 222-7474 or 800-222-7474 or 800.222.7474 or 800 222 7474
For international numbers (country code, city code, telephone number):
+22 (607) 123-4567 or + 22 607-123-4567 or +22 607 123 4567 
Note: When using international numbers, a recommended form is:
National:  (607) 123 4567  |  International:  +22 607 123 4567