One hundred and thirty-five people attended the conference.
- Spell out numbers one to nine in text.
- Use numerals for 10 and higher.
- Thousands take a comma: 2,450 not 2450.
- Large, round, even numbers used as approximations are spelled out:
The history spans some four thousand years of Western civilization.
- Very large numbers (million and higher) may be expressed with a combination of numerals and spelled-out numbers.
2 million people; 10 trillion is a large number
- These same rules apply to ordinals:
seventh place; 30th position; 135th award; third in line
Clusters of Numbers
Numbers within a sentence or paragraph that cluster together and are used in the same context should maintain consistency. If one of the numbers would normally be written as a numeral, use numerals for all in that same category. It is fine to have one category written with numerals and another with numbers spelled out:
There are 14 graduates, 25 alumni, 3 first-year students, and 1 senior in the program.
Middlebury faculty published 20 books in 2010; 5 were on the bestseller list, and they will be publishing 7 books next month.
When mother came, we found seven dead pigeons outside. That didn’t deter us from enjoying our snack. She served 5 kinds of cookies, 11 new beers, and 7 types of goat cheese.
Use numerals, even in text:
We are expecting to harvest 5.4 tons of corn.
Simple fractions: Spell out in text. Hyphenate the fraction if it represents a single quantity or when used as a modifier.
five-sixths of the population
He received two-thirds majority
But: I’m dividing my estate into five fifths to distribute to my heirs.
Whole numbers plus fractions: These can be spelled or expressed in numerals, whichever is most readable. (Do not link whole numbers to the fraction with a hyphen)
Three and three-fourths cups of flour should be enough to make pizza.
The recipe calls for 3 ¾ cups of flour.
Hyphenate measurements that serve as adjectives preceding a noun:
The bandage is a two-inch-long strip of gauze.
Place this four-foot block of wood in the fireplace.
Connect measurements with hyphens when the numbers represent a range, and they function as an adjective preceding a noun:
We knew that a tsunami might create 80-to-90-foot tidal waves.
References to money may be written as numerals or spelled out. If spelled, also spell the unit of currency, except when using very large numbers.
fifty cents; six dollars; seventy-five euro
$1 million; $10.3 billion
Always express percentages as a numeral-word combination, except in charts and scientific copy:
25 percent, 4 percent
Use numerals for specific reunions: 20th reunion, 10th reunion
Reunion events may be expressed this way: Reunion 2012, Reunion Weekend
45 degrees F (no period after the F within a sentence)
45°F (no spaces)