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Copyright by Stephen Wilbers, Ph.D.


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Rules for Numbers

From the University of Minnesota Style Manual

by Stephen Wilbers

Author of 1,000 columns
published in the Minneapolis Star Tribune & elsewhere

Also see numbers usage and numbers exercise.




  1. In nonscientific writing, spell out exact numbers of less than 10; use figures for numbers of 10 or more. Follow this rule for both ordinal and cardinal numbers.

four years                            12 courses

third-quarter freshman          21st precinct

  1. Treat consistently throughout a sentence or paragraph all numbers referring to the same category. If the largest number is 10 or more, use figures for all the numbers.

Of 117 campus newsletters, 4 are issued weekly, 35 are issued monthly, 72 are issued quarterly, and 6 are issued annually.

During the past four months, the two newest recruits to the campus police force have issued 49 parking tickets, 2 of which were for double parking,


  1. When it is the first word of a sentence, spell out a number that would normally be written as a figure. If possible, rephrase a sentence to avoid beginning with a number.

Thirty-nine percent of the students attending day school voted.

Of the students attending day school, 39 percent voted.




  1. Do not use st, nd, rd, and th after dates to indicate ordinals.

Student elections are scheduled for May 26.


Student elections are scheduled for May 26th.




  1. Use figures for monetary amounts. Use cents with amounts of less than a dollar; use the dollar sign for amounts of a dollar or more.


Back then you could send a letter for 4 cents.

The fee amounts to about $1.50 per student.


  1. Do not use ciphers (zeros) with even dollar amounts, except for consistency within a series.

Students pay only $1 per film.

She paid $27.50, $18.00, and $16.95 for the three texts.


  1. For monetary amounts of more than a million dollars, use the dollar sign and spell out million, billion, etc. Never use a hyphen within such numbers.

$2 million     a $4.87 billion loan     $10 million to $12 million




  1. Use figures for decimals and percentages. In nonscientific copy, use the word percent; in scientific or statistical copy, use the symbol %. [But note that the symbol % is becoming more common in business writing.]


Less than 2 percent of the annual budget goes toward student aid.

Total saturated fatty acids were 48% and 37% for the two carcasses.




  1. Do not repeat a spelled-out number in figures.

The course must be taken sequentially over three quarters.


The course must be taken sequentially over three (3) quarters.

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