Note that these rules are appropriate within the context of formal writing.
Spell out numbers from one to nine for both ordinal (first, third, tenth, etc.) and cardinal numbers (1, 3, 10, etc).
The conventions within engineering, for example, may differ from those within economics.
In this article, we present 10 rules or guidelines to spell out numbers.
It is generally best to write out numbers from zero to one hundred in nontechnical writing.
In scientific and technical writing, the prevailing style is to write out numbers under ten.For example, spell out any number that precedes another number expressed in numerals.Example Avoid: The difference from baseline stimulus sensitivity scores for each condition during the 3 20-min periods following baseline.when the number begins a sentence, title, or heading examples: Forty-eight percent of the sample..., Twelve students improved... common fractions examples: one fifth of the class..., two-thirds majority c.The rules regarding numbers in writing vary among academic disciplines.Example 1 Avoid: He served 9 years in prison following his 1954 break.Use: He served nine years in prison following his 1954 break.Use: The difference from baseline stimulus sensitivity scores for each condition during the three 20-min periods following baseline.Spell out indefinite numbers and amounts, including large approximations.While there are exceptions to these rules, your predominant concern should be expressing numbers consistently.Here’s a tip: Want to make sure your writing always looks great?