Numbers

How you treat numbers is mainly to do with style. A common style is ‘zero to nine, 10 and above’ (or ‘zero to ten, 11 or above’).

Beyond a certain number, though, if the numbers aren’t specific it looks terrible to include them as figures (such as ‘1,000s’). So you might add ‘but hundreds, thousands’ to your style instruction.

You will need to know whether you are including commas or another type of separator in numbers from 1,000 onwards. If it’s up to you to decide, it’s a good idea to include separators, otherwise numbers in the early thousands could be mistaken for years (e.g. 2021).

You will also need to consider how you’re dealing with fractions and high numbers, like millions and trillions, as well as ages, dates, percentages and more. You should also specify whether figures only are used with measurements such as lb and km – this is a common style. In fiction, it’s more common for numbers to be rendered as words than as figures.

Throughout, the most important thing is to record all variations and keep everything consistent. Explain in as much detail as you can on the style sheet how you are treating numbers in every context that arises in the document.

For more detail, check out Graham Hughes’s CIEP fact sheet, ‘Editing and proofreading numbers’.