Updated: Jul 28, 2020
Rules for spelling numbers out and writing them numerically vary. Grammar handbooks state that numbers of one or two words should be spelled out while numbers of at least three words n should be written numerically.
The exception to all rules about writing numerically versus spelling out a number occurs when a number is the first word of a sentence. In these instances, numbers always should be written out.
Sentence: 9 of the 109 participants responded similarly to the three questions focused on community engagement.
Edited Substance: NINE of the 109 participants responded similarly to the three questions focused on community engagement.
The number is changed to the word “nine” simply because it starts the sentence. Some writers seek to keep all of their numbers in the same format in a sentence; however, writers should know and adhere to grammar or style guide rules regarding numbers.