Did you know there are rules and conventions surrounding writing with numbers?
Many people don’t.Most people aren't aware there are rules and conventions for writing with numbers. Click To Tweet
While rules surrounding the use of numbers and numerals in writing aren’t as strict as those that apply to spelling and grammar, proper use of them, or sticking to an agreed Style Guide can make your writing much easier to read.
Here are some basic rules when writing with numbers.
Know when to spell them out
Generally speaking, numbers from one to nine, should be spelled and numbers 10 and above can be written using numerals.
When discussing the subject of money, stick to numerals. It is much easier to read. When talking about cents, either write it in full (e.g. “sixty cents” or “60 cents”). Avoid “$0.60”.
To avoid any confusion, use numerals when writing out decimals. (e.g. “1.5 per cent”, NOT “one point five per cent”).
Use a comma
Commas should be used in numbers of four or more digits to separate hundreds, thousands and millions, etc. (e.g. 1,500; 100,000, etc.).Avoid starting sentences with numbers. Re-write the sentence where possible as this makes for easier reading. Click To Tweet
Start sentences with words, not numbers
Avoid beginning sentences with numbers. Where possible, re-write the sentence. Where it’s not possible, then spell out the word. (e.g. “Twenty thousand people” instead of 20,000 people). In the case of spelling out compound numbers, use a dash (e.g. “forty-five people”, rather than “forty five people”).
When writing speeds, it’s preferable to use numerals, simply because that’s what most people read when they drive. So, the speed limit is “60km per hour”, not “sixty km per hour”.
Years, decades and centuries
You should write the year using numerals (e.g. 2016). However, when it comes to decades or centuries, a spelled out version is preferable (e.g. “the nineties” or “seventeenth century”).
When referring to time, keep it simple and use numerals when referring to time (e.g. “5.15am”, instead of “five-fifteen in the morning”).When writing about percentages, stick to a format and be consistent. Using '%' or 'per cent' are both acceptable. Click To Tweet
Percentages can be tricky
Ultimately, it will come down to the style guide of the organisation you are writing for. If you work for a scientific or medical industry, it may be preferable to express percentage with the symbol ‘%’. However, in more formal writing it is preferable to use ‘percentage’ or ‘per cent’ instead.
Fractions should be expressed in a format that is easy to read. That means the top figure in superscript, followed by a slash and the second number in subscript (e.g. “1/8”). Do not use the form “one eighth”.
When writing about degrees, always use numerals. For example, 9 degrees, NOT nine degrees. You may also wish to use the symbol “°”. However, remember that there should be no space between the numeral and the symbol. (e.g. 35°C).
What about recipes?
Recipes are less formal and need to be easy to read and understand. For this reason, express measurements in numeral form. (e.g. “2 tablespoons”, “1 ½ cups”, etc.).
Sometimes large numbers are best rounded up or down, and expressed as a combination of written word and numerals. For example, “200 million” is easier to read than “200,000,000”. However, if you need to write an exact number, use the numeral format (e.g. “200, 186, 348”).
Numbers close together
Every now and then, you will come across two different numbers written next to each other. For example, “we surveyed 12 45-year-olds”. In this case, spell out one of the numbers (usually the lowest number), so it looks like this “we surveyed twelve 45-year-olds”.
Depending upon the genre of your writing and who your audience is, you may find you need to bend some of the above rules a little bit. That’s fine. Just make sure that whenever you’re writing with numbers, you’re consistent across the board.
The best way to do this is to develop your own in-house Style Guide.
If you’d like help developing a Style Guide for your business, or need help with your writing needs, please contact me. I’d would love to work with you.