TCMOS – Numbers – Chapter 9

Sunday, December 29, 2019
Blog #8 of my learning from #TheChicagoManualOfStyle.

Today is the last blog of 2019, also marking the midpoint of The Chicago Manual of Style (TCMOS) topics.

The topic today is numbers.

Numbers are unavoidable parts of our books, journals, articles, and blogs. We deal with money, dates, times, and statistics. Read on to learn whether to spell, hyphenate, and punctuate.

To Spell or not

General rule: TCMOS advises spelling whole numbers from zero through one hundred and their round multiples. The rule applies to:

1. Distances, lengths, areas, and so on.
2. Money
3. Date and time
4. Ordinals
5. Cardinals

Exception #1: Spell out multiples of round numbers, but use a numeral for precise counts.

Fifty-five thousand people fled the nation.

The official count of people who fled was 55, 325

Exception #2: Always spell out a number starting a sentence.

Two hundred ten athletes competed in the tournament.

In all, 210 athletes competed in the tournament.

Please note: 

1. “And” is omitted in “two hundred ten.” 
2. If a year starts a sentence, spelling it out will be awkward. TCMOS recommends rewording and removing it from the start. So “the year 1980” sounds better than “nineteen eighty was.”
3. If a second number appears after the first spelled-out one, use numerals for the latter. One hundred candidates of 250, and be consistent in your choice across your work.

Before I proceed further, it’s important to understand the following definitions.

Ordinal Numbers: Numbers that state a position of something. First or 1st. July 21st. 

Cardinal Numbers: Numbers that aren’t ordinal. 1, 2, 3 . . . one, two, three.

The “general rule” of spelling numbers applies to ordinals and cardinals alike. Ordinals are bound by a few more rules, and I’m guilty of violating them.

1. Don’t superscript the nd, etc. 22nd (hard to fool a MS word processor.)
2. Avoid ordinals in certain dates. See the date section below.

Tip: Whether spelling or using numerals for number category, be consistent with your choice. Examples of number categories are years, dates, ordinals, cardinals, etc. Yes, you can break this rule to enhance readability.

Exception #3: Spell out a simple fraction even when a whole number precedes it. However, if the fraction is large, use numerals instead. One-quarter mile. 5 ¼ inches tall.

Exception #4: When using numbers with abbreviations, use numerals. 50 km. But spell a measurement unit without a number. We measured in pounds (not lbs).

In a range, repeat the unit only if it’s closed to the number. 30%-60% (A closed unit contains no space between the number and itself). 2 * 6 cm (cm is not repeated because it’s not closed => there’s a space between the number and unit).

Exceptions #5: Percentages (not percent) are usually expressed in numerals (instead of spelling out). In a novel that is non-scientific, use the spelled-out word percent instead of symbol %. 5 percent. 

• It’s better to rephrase a sentence starting with a percentage to not have to spell it out
• Percent = adverb. Percentage = noun. Don’t interchange.
• Large decimal fractions are also numeric. Use a zero to the left of decimal instead of blank

Money:

• The general rule applies to money too
• Note the singular verb form of the following: The fifty-five dollars was saved
• Non-US currency should be spelled out to avoid confusion. New Zealand dollars. Mexican pesos. 
• While $30 is a closed unit/number form in numerals, but space exists between thirty dollars (spelled out). Don’t write $thirty or 30 dollars.
• Exception #6: Money amounts larger than one hundred dollars are expressed in numerals.
• Please refer to TCMOS, 9.25 for a notation for money and dates.

Exception #7: Yes, general rule states spelling out numbers less than one hundred or round multiples. But page numbers, chapter numbers, parts, volumes, etc. are expressed in numerals. I’m glad to learn this as I have titled my blogs with chapters numbers from TCMOS set in numerals.

DATE / TIME

Exception #8: Years are expressed in numerals except when starting a sentence, and if so, rephrase the sentence is your recommended options.

Use cardinal numbers for specific dates (instead of ordinals) even if these are pronounced as ordinals. September 1, 1980. (not 1st) 26 March 2010.

Exception #9: decades are spelled out or numeral. See examples below from TCMOS noting that s after the year calls for no apostrophe.

The 1940s and 1950s

The forties and fifties

Exception #10: Spell out day times in even, half, and quarter hours, but for the more precise times, use numerals.

• Always spell the time with o’clock. Use o’clock for less-precise time
• 7:12 p.m. is precise and set in numerals with a lowercase p.m. I could have said 7:00 p.m. instead of seven o’clock but note the zeros and the spelling-out rule.
• Don’t say twelve o’clock or 12:00 a.m.; Use instead noon or midnight, never both together.

Exception #11: State, federal, and interstate highways are designated by Arabic numerals. US Route 41. I-90 or Interstate 90.

The following are also spelled out if one hundred or less.

• Street numbers
• Avenues
• Successive governments
• Political or judicial divisions (Tenth circuit, 101st precinct)
• Military units
• Building numbers

To Hyphenate or Not

Number + noun: Hyphenate before a noun (bolded) else open

• Hundred-meter race
• Two-hundred-meter race
• A 252-page book
• A six-foot-four woman
• She is six feet two (not hyphenated, subject preceded the number).
• A five-pound baby

Number + abbreviation: Always open. 100 m. 2 kg.

Number + percent: Not hyphenated unless giving a range (40 percent).

Number, ordinal, + noun: Hyphenated before a noun, else open. On the third floor, take the twenty-first cubicle. Second-best decision.

Numbers, spelled out: Twenty-one through ninety-nine are hyphenated; otherwise open.

• Twenty-seven
• Three hundred
• Nineteen forty-five
• Four hundredth

Age:  a three-year-old boy but the girl is four years old.

Fraction:

• I’ll be late by a half hour (not hyphenated; noun form is open)
• But hyphenate a half-hour session (adjective form is hyphenated)
• My homework is three-quarters done (adverb form is hyphenated)
• Skip hyphen when already hyphenated element: one twenty-fifth share

Money: Same rules applies: hyphenate before a noun, else leave it open. A multimillion-dollar deal. A deal worth twenty million dollars. When used with symbol $, leave it open. $20 million deal.

Time: Usually open, hyphenate before a noun (same rule). At four forty. Five-fifty train.

Plurals and Punctuation of Numbers

• Numerals form plurals by adding s with no apostrophe. Sixes. 206s. 1980s.
• No commas used in page numbers, line numbers, addresses, and years.
• In Germany, Italy, and Russia a comma is used for a decimal
• The following formats for telephone numbers are acceptable:
  • (000) 000-0000
  • 000-000-0000
  • 1-000-000-0000
• Ratios: Spell out ratio of whole numbers. Two-to-one ratio. 2:1 has numerals, however.
• If using to and from, no en dash is required for range
• Inclusive spelled-out numbers are joined by to, not by an en dash. Use en dash for numerals that are inclusive.

My Takeaway

Rules are important. Learning to follow them is as important as learning to break them.

The year is turning, and I won’t remind myself how old I’m getting. But let that hope burn inside you, illuminate that darkest fear, that bleakest of yearning, and that impossible dream. Welcome 2020!

Source: The Chicago Manual of Style, SEVENTEEN EDITION.

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