In print or online, for charts and graphs, use numerals.
See the The students collected 114 books for the sale, 12 of which were first editions. —Use either a figure or a word—not both: five rooms, not five (5) rooms.
The document will make use of small numbers, large numbers, decades, and statistics.
Thankfully, when using numbers in writing, you can count on a few conventions that apply to most situations; just be sure to consult your specific style guide if one has been assigned.
Correct: There were twelve 4-year-old children waiting for the librarian to begin story time.
Correct: There were 12 four-year-old children waiting for the librarian to begin story time. If you are referring to a specific year (e.g., 1955), use the numeral.Decades or centuries are usually spelled out, especially if the writing is formal. Always strive for consistency, even if it overrides a previous rule.For example, if your document uses numbers frequently, it is more appropriate for all numbers to remain as numerals to ensure that usage is uniform throughout.The main purpose of this rule is to avoid confusing the reader.Incorrect: There were 12 4-year-old children waiting for the librarian to begin story time.Correct: The library acquired 5 new mystery novels, 12 new desktop computers, and 17 new periodicals. If your work must follow the rules of a specific style guide, understand that they all have rules for spelling out numbers that may differ slightly from the rules listed above.For example, MLA style indicates that writers may spell out numbers if they are not used too frequently in the document and can be represented with one or two words (e.g., ) be expressed as words.A number of specific rules for spelling out numbers are outlined in section 9.1 of the Chicago Manual of Style.Your ultimate authority will always be a style guide, but in the absence of one, following the rules outlined above will help you be consistent in your use of numbers in writing.Correct: The circulation of library materials increased by 4.5% in 2015.When two numbers come next to each other in a sentence, be sure to spell out one of these numbers.