Many things influence whether you express numbers in figures or in words. Sometimes it’s your profession, and sometimes it’s the editing style of your organization.
Here are some common number usage guidelines to follow to produce consistent documents.
General Number Guidelines
When to use figures
- in numbers 10 and above (e.g., He signed 14 copies of the document.)
- for reporting sport scores (e.g., The team won with a score of 8 – 12.)
- in cases when there are large and small numbers in one list (e.g., On our cycling trip we covered 9 km the first day, 13 km the second day, and 21 km the third day.)
When to spell out numbers
- in numbers from 0 – 9 (e.g., I bought three new chairs for the conference room.)
- at the start of a sentence (e.g., Twenty-four managers made it to the training session.)
- in fractions below 1 (e.g., He has a five-eighths share of the company earnings.)
- in approximations (e.g., There were approximately a hundred people at the conference.
There are some exceptions to this rule when you might use figures.
- impact (rulings, decisions, scores, votes and odds to make results easier to see on the page)
- style consistency (series of items within one sentence)
Examples:
The vote was tied 4–4. (impact)
We need to buy the following: 2 printers, 8 reams of paper, and 12 pads sticky notes. (style consistency)
Consistency Is Key
Many people don’t think about the style choices they make when using numbers in their writing. As with capitalization, being consistent when using numbers is important.
Imagine you’re working on a report, and the ideas and recommendations you’re presenting in this report might change how your business operates. However, you have a consistency issue. Sometimes you spell out a number, such as nine, and other times you use a figure. Your date formatting keeps changing. You don’t represent fractions and decimals consistently. When referring to time, you sometimes use pm and other times P.M.
Why is inconsistency in your writing problematic? Some readers likely won’t notice a few inconsistencies. However, if your report is full of them, you risk distracting your readers and undermining your credibility as a professional. Readers may start to focus on your formatting instead of your great ideas or the meaning of your numbers, which may in turn reduce the chances of your recommendations being accepted.
When you use consistent formatting with numbers, your documents are easy to read. People will focus on the meaning of the content, not the formatting.
Additional Guidelines
Here are some other general guidelines for writing with numbers.
- Spell out a number that begins a sentence, even if it’s greater than nine. If the number is large, reword the sentence to move the number away from the beginning. (e.g., Twenty volunteers shared their time and had a great experience.)
- When referring to money that is a round value amount, omit the decimal and zeros. (e.g., We spent $50 for the shelving unit and $135 for the filing cabinet.)
- When writing about time, use the 12-hour clock and the abbreviations a.m. and p.m. to designate if it is before noon or after noon. (e.g., The meeting is from 8:15 am to 9:30 am. The lunch meeting is booked from 11:30 AM–12:30 PM.) Note: You can use either am/pm, AM/PM, a.m./p.m., or A.M./P.M. However, pick one of these styles and use it consistently throughout your document.
- Use minute values to maintain a parallel structure and sentence balance. (e.g., The meeting ran from 8:00 am to 10:15 am.) Note: If you use the word "from" before the first time, then use the word "to" in front of the second time for balance. You can choose to use a dash instead of the words from and to. Make sure you pick one style and use it consistently throughout your document.
- When writing dates in a document, omit the ordinal (e.g., 1st, 2nd, 3rd or 4th) when writing a full date line (month, day, and year). (e.g., May 20, 2011)
- If you use fractions in your writing, use figures with mixed fractions above one. (e.g., We delegated 1½ of the jobs to Team B.)
- If you use ordinals, follow the general guidelines for numbers: Spell out first to ninth; use figures for 10th and higher. (e.g., It’s my third interview of the day. He was the 12th person to join our firm full time.
If you would like a reference guide to keep at your desk, check out The Eclectic Writing Series. Solving the Grammar Dilemma addresses capitalization, numbers, punctuation, apostrophes, pronouns, agreement and parallel structure.
