Harvard Wikis will be briefly unavailable between 7am and 9am on Monday, September 20th for a maintenance event. Apologies for the inconvenience!
Page tree
Skip to end of metadata
Go to start of metadata

Cardinals and Ordinals

All numbers are spelled out below 101. We always spell and cap ordinals when referring to Reunions in running text and on book covers. 

Jonas ate thirty-two pieces of sushi. 

Mr. and Mrs. Winter are celebrating their fifty-third wedding anniversary.

I just got my Tenth Report in the mail. 

I can't wait to attend my Sixty-fifth Reunion!

Large round numbers should be spelled out.

one hundred

two thousand

twenty thousand

250,000 (not quite “round” enough)

Very large numbers or dollar amounts should be expressed in figures (see CMS 9.8).

2.3 million people

$54 billion 

In addresses and running text, only use "d" not "nd" for abbreviation. No superscripts.

122d not 122nd

123d not 123rd

Measurements of quantity

Fractional quantities expressed in numerals.

8 1/2-by-11-inch piece of paper

Scientific measurements and grouped statistical information expressed in figures:

45 pounds, 3 cubic feet

1 win, 7 losses, 3 ties (scores appear in figures)

In a paragraph of mixed scientific and general numbers, all should be expressed in figures for consistency.

Heights are generally spelled out.

She is six-foot-two.

The word “percent” is written out, but numbers appearing as percent are expressed as numerals.

97 percent of the Class.

For temperatures, the word "degrees" is written out, but numbers appearing as temperature are expressed as numerals, with temperature scale spelled out.

30 below freezing

74 degrees Fahrenheit

Running text formatting

Always spell out numbers at beginning of sentence, including years (CMS 9.5).

Nineteen ninety-nine found me working for State Department.

Format round hours with a colon and two zeros and set ante/post meridiem in small caps.

7:00, 8:00

12:37 am, 3:28 pm


Interstates and route numbers appear as numerals.

Time periods

Decades can be expressed as numerals with an s, but do not include an apostrophe s, unless it is to form the possessive:

I loved the ’60s.

When we lived in New York in the ’70s . . .

Centuries, however, should be spelled out and downcased:

"The twentieth century saw many technological advances.”


Lists in running text should use enclosed numerals indicating list divisions in parentheses.

John Lithgow advised the Class of 2005 to (1) be creative; (2) be useful; (3) be practical; and (4) be generous.

Vertical lists should use a format of: 1., 2., 3., 4. , etc., aligned vertically down the page.


  • No labels