Numbers can often present different style questions in American English. When should we spell them, and when shouldn’t we? In particular, what are ordinal numbers and what are cardinal numbers, and how do we treat them? Mastering these distinctions will refine your precision in your daily writing.

For this discussion, we’ll review style guidance from our two primary supporting references, *The Associated Press Stylebook *and *The Chicago Manual of Style.*

*AP *is popular style for everyday communications such as newspapers, magazines, and online journalism. *CMOS *is widely regarded as a style authority for more-formal publications such as books and academic writing. You can choose to follow the style format that is best suited to you and your audience.

Ordinal numbers are those that indicate rank, order, or position. Ordinal numbers do not express quantities, an important distinction from cardinal numbers.

Concerning ordinal numbers, AP advises to spell out *first* through *ninth*:

Keersten just won thesixthgold medal of her illustrious ice-skating career.

That is thefourthguitar string I’ve broken in the last few weeks.

For ordinal numbers greater than *ninth*, AP directs to use figures:

Vithu recently celebrated his30thbirthday.

Jean has crossed her13thmile of the marathon.

*The Chicago Manual of Style* advises to spell out *first* through *one hundredth*:

Vithu recently celebrated histhirtiethbirthday.

I’m pretty sure that’s theone hundredthtime you told me that.

For ordinal numbers greater than *one hundredth*, CMOS directs to use figures:

Today is the175thanniversary of the founding of the village.

The labor strike has reached its205thday.

Cardinal numbers—also known as counting numbers—are used to specify quantities (i.e., they identify how many). They are what come to mind most often when we think of numbers. Unlike ordinal numbers, they do not specify rank, order, or position.

AP advises to spell out *one* through *nine*:

Blaine hastwodogs, and Ray-Ray hasfive.

Gator was held back after his junior year of high school, so he went tothreetotal proms.

For cardinal numbers greater than *nine*, AP typically directs to use figures:

Victor owns32miniature replicas of different types of airplanes.

The labor strike has reached day205.

* *CMOS advises to spell out *one *through *one hundred*:

Blaine hastwodogs, and Ray-Ray hasfive.

Victor ownsthirty-twominiature replicas of different types of airplanes.

For cardinal numbers greater than *one hundred*, CMOS directs to use figures:

The state-park expansion now includes an additional220acres for wildlife preservation.

That rampart is1,185years old.

The exceptions to this CMOS guideline are whole numbers combined with *hundred*, *thousand*, *hundred thousand*, *million*, *billion*, etc.

Approximatelytwo hundred thousandpeople attended the city parade and celebration.

Scientists estimate the earth to be more thanfour billionyears old.

Even after a good review, the difference between ordinal and cardinal numbers can sometimes still be evasive.

One device for recalling the distinction is to associate *ordinal *with the concept of *order.* Ordinal numbers also will not be expressed as counting digits (*one, five, ten, etc.*) and, when written, will usually include a suffix: *10th, 35th, 101st*.

Similarly, you can remind yourself that *cardinal *relates to *counting*, and both words begin with a *c*.

Certain numbers can be classified as *nominal *numbers. This means that they identify something as opposed to counting or ordering it. Just a few examples might be a zip code, a telephone number, or a sports player’s uniform number.

ExamplesJason lives somewhere in Beverly Hills

90210.The new number for Doggie Dearest Grooming is

888-555-3644.We will always remember the Chicago Bears’ legendary

34, Walter Payton.

We’ve reviewed the primary basics for treating numbers in your writing according to a more-formal style (CMOS) or a daily, slightly less-formal style (AP).

There are two more leading items to keep in mind that both AP and CMOS agree on.

1) If a sentence begins with a number, the number is typically spelled out:

Fortyyears is a long time to drive the same car.

One hundred twentystudents attended the rally.

If the starting number would be laborious to write out, try rewriting the sentence:

One thousand nine hundred seventy-twopeople responded to the offer for the free tickets.

The offer for the free tickets attracted1,972responses.

2) It is acceptable to use numerals if multiple items are in a related category or if spelling the numbers would make the content too thick or cumbersome:

Chester’s farm includes 12 cows, 5 horses, 34 chickens, and 11 goats.

The ages of the judges on the panel are 64, 38, 29, 53, and 32.

Rules for Writing Numbers

Writing Dates and Times

Numbers: Words or Numerals?

Identify if the number(s) in each sentence are ordinal or cardinal. The sentences will vary between AP and CMOS style.

1. This is the __fourth__ time I’ve called to make an appointment. [ordinal / cardinal]

2. The band’s lead singer said the candy bowl must include __74__ green M&Ms, __56__ red ones, and __102__ yellow ones. [ordinal / cardinal]

3. Markus set the record for the discus throw with his __sixth__ attempt. [ordinal / cardinal]

4. __Ten__ days is the normal waiting period to receive the package. [ordinal / cardinal]

5. The distance between Earth and the moon is __238,855__ miles. [ordinal / cardinal]

1. This is the __fourth__ time I’ve called to make an appointment. **ordinal**

2. The band’s lead singer said the candy bowl must include __74__ green M&Ms, __56__ red ones, and __102__ yellow ones. **cardinal**

3. Markus set the record for the discus throw with his __sixth__ attempt. **ordinal**

4. __Ten__ days is the normal waiting period to receive the package. **cardinal**

5. The distance between Earth and the moon is __238,855__ miles. **cardinal**

**If the article or the existing discussions do not address a thought or question you have on the subject, please use the "Comment" box at the bottom of this page.**

In your article you used “zip code,” while that is supposed to be a registered trademark beginning with four capital letters, ZIP Code.

The

ChicagoManualofStyleuses “zipcode” with no capital letters. TheAssociatedPressStylebookuses “ZIP code” with no capital “c” for “code.” Either form is correct.