The Ins and Outs of Hyphenating Numbers: A Comprehensive Guide
Hyphenation rules can be tricky, especially when dealing with numbers. Do you hyphenate "twenty-one" but not "two hundred"? What about "one-half" versus "two halves"? This article breaks down the rules of hyphenating numbers to clear up the confusion and help you write with confidence.
Understanding the Basics
Hyphenation helps to prevent ambiguity and improve readability. It essentially acts as a visual cue to indicate that two or more words should be treated as a single unit. The basic rules for hyphenating numbers are:
1. Numbers from twenty-one to ninety-nine: Always hyphenate these two-word numbers, including compound numbers like "twenty-three" and "sixty-seven."
2. Fractions: Hyphenate fractions that are written out as words, like "one-half," "two-thirds," and "three-quarters." However, when the fraction is expressed with numerals, the hyphen is not used (e.g., 1/2, 2/3, 3/4).
3. Numbers used as adjectives: Hyphenate numbers used as adjectives when they precede a noun, like "a two-week vacation" or "a five-mile walk."
4. Compound numbers: Hyphenate compound numbers (those with multiple words) when they act as a single unit, like "two-hundred-fifty" or "four-thousand." However, there's a caveat here: don't hyphenate compound numbers in large numbers like "two million" or "three hundred thousand."
5. Consistency is key: Be consistent in your hyphenation throughout your writing. If you choose to hyphenate a number in one instance, stick with that choice throughout your text.
Additional Notes and Exceptions
- Numbers greater than ninety-nine: These are generally not hyphenated. For example, "one hundred," "five thousand," and "two million" are all written without hyphens.
- Numbers expressed as numerals: Numbers written as numerals (e.g., 1, 2, 3) are generally not hyphenated.
- Age: You can choose to hyphenate ages depending on context. For example, "a two-year-old child" or "a child who is two years old."
- Style guides: Consult your specific style guide (such as the Chicago Manual of Style or the Associated Press Stylebook) for additional guidance on hyphenation rules, as there can be variations.
Examples
- Correct: a twenty-one-year-old student, a two-thirds majority, a four-mile hike, three-hundred-fifty people
- Incorrect: a twenty one year old student, two thirds majority, a four mile hike, three hundred fifty people
Conclusion
Hyphenating numbers is a relatively straightforward process once you understand the basic rules. Remember to be consistent, pay attention to context, and consult your style guide for any specific guidelines. By mastering these rules, you'll be well on your way to writing clear, accurate, and professional-looking content.
