1.8 Basic Guideline when Writing Numbers
Professional communicators have a few debate points on writing numbers, but most of the advice is consistent.
Any number less than 10 is to be written in words. Generally, the word is followed by the numeral in parenthesis.
Zero (0), one (1), two (2), three (3), four (4), five (5), six (6), seven (7), eight (8), and nine (9).
Numbers greater than nine are written as digits until you reach the millions. Then, for ease of reading, you may write large numbers in the following style: 3.2 million, half a billion, 453 billion, 1.22 trillion, and so on.
Example
I have a sentimental attachment to these two (2) things.
That happened two months ago.
Twelve percent of men and women experience issues with seeing colours.
Tips
- When writing a number less than one and greater than -1 in a decimal format, include a leading zero before the decimal point. That is, write “0.5” and not “.5” or “-0.25″ and not -.25”; this will provide greater visual clarity.
- Negative numbers are always written as digits, showing the negative symbol before the number.
- If your number has units attached or is expressed as a fraction or in some mathematical equation, always express it as digits. Here are some examples: $1.00, 2%, 3/4, 5°, etc.
- You should usually use the percent symbol with percentages, but writing “percent” is also acceptable. Whatever choice you make, be consistent. Do not write “per cent” with a space in it.
- For APA style, if the numbers precede a unit of measurement, use the numerals.
Examples
5-mg dose
A ratio of 4:1
6%
Within the 4th percentile
Fun activities for Grade 8 students
Exceptions
If you begin a sentence with a number, you’ll write out the whole number to avoid confusion. Here’s an example: “Fifty-five years ago, music reached its zenith.”
If you’re keeping score at a sporting event or putting a number on the back of a player’s jersey, the numbers are always expressed as digits. Addresses are virtually always expressed as digits, even when only a single digit is part of the address, and commas are not added in street numbers of four digits or longer.
“Appendix B: Writing Numbers” from Professional Writing Today Copyright © 2022 by Sam Schechter is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License, except where otherwise noted.—Modifications: Edited for brevity; Added examples.
