Use a combination of figures and words for numbers when such a combination will keep your writing clear.For example, spell out any number that precedes another number expressed in numerals.
Here is a quick overview of the rules for writing numbers. (More natural than I got only thirty-five marks in English.) One-word numbers can be spelled out. SI recommends that a space should be used to separate groups of three digits. Write ‘They sold 400,000 copies on the first day’ instead of ‘400,000 copies were sold on the first day.’ Centuries should be spelled out.
Small numbers Numbers smaller than ten should be spelled out. (NOT ‘2 birds were sitting on a branch.’) Two-word numbers should be expressed in figures. Examples are: eleven, thirteen, twenty, thirty etc. In the nineteenth century But some writers also use a combination of numbers and letters.
That is, spell out common fractions like one-fifth, two-thirds, etc, Example 1 Avoid: Morson estimated that up to 2/3 of all colorectal carcinomas arise from adenomatous polyps.
Use: Morson estimated that up to two-thirds of all colorectal carcinomas arise from adenomatous polyps.
For example, “The sixties was known for rock-n-roll” or “The twentieth century made huge technological advances.” Let’s say you decide to use numeral starting at 21.
That means you’ll always use numerals for numbers like 99, 515, 800, 1,600, 73,000, and 429,000. But when you start getting into the millions and billions, it’s much better to write 80 million instead of 80,000,000.
Example Avoid: The difference from baseline stimulus sensitivity scores for each condition during the 3 20-min periods following baseline.
Use: The difference from baseline stimulus sensitivity scores for each condition during the three 20-min periods following baseline.
The rules regarding numbers in writing vary among academic disciplines.
The conventions within engineering, for example, may differ from those within economics.