The One Plus 8 Pro Display Quality Surprised Tech Reviewers

BGR: Xreal One Pro Review: The Best Display Glasses You Can Get Lifehacker: Which Are the Better Smart Display Glasses: RayNeo Air 4 Pro vs. XReal One Pro Which Are the Better Smart Display Glasses: RayNeo Air 4 Pro vs. XReal One Pro pronouns - "One of them" vs. "One of which" - English Language Learners ... As @PeterShor points out, in this case "one" is the pronoun, and would never be numeric. Beyond that, as a general rule, spell out numbers 1-9, but for technical writing, it may be appropriate to always use the numeric version when you're referring to a numeral (as opposed to the pronoun example above).