Ages
Editorial Voice
Ages
For ages, always use figures. If the age is used as an adjective or as a substitute for a noun, then it should be hyphenated. Don’t use apostrophes when describing an age range. Examples: A 21-year-old student. The student is 21 years old. The girl, 8, has a brother, 11. The contest is for 18-year-olds. He is in his 20s.