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Rules on Writing Numbers

This week my 11-year-old daughter had an assignment on writing numbers. One of the rules on her assignment sheet stated, "Numbers that are expressed in fewer than four words are spelled out."

That rule sounded like trouble to me. After all, do we really want to write seventeen thousand sixty? I would much prefer 17,060, but the sixth graders’ rule seemed to demand the spelled-out version.

Some of us need to coach our children in writing well; the rest of us need to write better on the job. Those are two good reasons for reviewing the basic rules of how to render numbers–in words or figures.

The following rules agree with The Gregg Reference Manual, Microsoft Manual of Style for Technical Publications, and The Associated Press (AP) Stylebook.

1. When a number begins a sentence, spell it out.

Seventeen people called to report the accident.

2. Generally, spell out numbers from 1 to 9; use figures for 10 and above. Note: The Gregg Reference Manual spells out numbers from 1 to 10.

The 11 participants could not be grouped in pairs, trios, or quads.

The seven participants broke into two groups of three and four.

3. Use figures (even when the numbers are less than 10) for numbers of technical significance: percentages, pages, sizes, money, measurements, clock time, coordinates, etc.

See page 6 for the explanation.
Since 2004, turnover has been approximately 9 percent.
Tickets for the 2 p.m. webcast are almost sold out.

4. For dates, use figures and cardinal (1, 2, 3)–not ordinal (1st, 2nd, 3rd) numbers.

The March 17 meeting has been rescheduled.
On April 4, 2001, we opened this branch office.

5. When numbers apply to the same thing, render them the same way.

These three conference rooms hold groups of up to 8, 16, and 24 people. [not eight]

Sometimes a number needs to stand out, even when it is less than 10. For example, in resumes our years of experience should catch the reader’s eye.

. . . including 7 years as a program manager

That’s the reason the numbers in my second rule above are in figures (numbers from 1 to 9)–so they stand out.

I’m guessing that my daughter’s assignment included unusual number rules and examples because the textbook the teacher is using is simply out of date. Everyone should have current reference books. How about you?

If you’ve been surfing the Internet for rules on numbers, grammar, punctuation, and usage, why not invest in a new style manual that will answer virtually all your questions? To choose one that matches the work you do, check out my Recommended Books.


Other search spellings: nubmers, numers, wrting, writng, grammer, techncial,

Posted by Lynn Gaertner Johnson
By Lynn Gaertner-Johnston

Lynn Gaertner-Johnston has helped thousands of employees and managers improve their business writing skills and confidence through her company, Syntax Training. In her corporate training career of more than 20 years, she has worked with executives, engineers, scientists, sales staff, and many other professionals, helping them get their messages across with clarity and tact.

A gifted teacher, Lynn has led writing classes at more than 100 companies and organizations such as MasterCard, Microsoft, Boeing, Nintendo, REI, AARP, Ledcor, and Kaiser Permanente. Near her home in Seattle, Washington, she has taught managerial communications in the MBA programs of the University of Washington and UW Bothell. She has created a communications course, Business Writing That Builds Relationships, and provides the curriculum at no cost to college instructors.

A recognized expert in business writing etiquette, Lynn has been quoted in "The Wall Street Journal," "The Atlantic," "Vanity Fair," and other media.

Lynn sharpened her business writing skills at the University of Notre Dame, where she earned a master's degree in communication, and at Bradley University, with a bachelor's degree in English. She grew up in suburban Chicago, Illinois.

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