Numerals
DO
Always use Arabic numerals for measurements (age, weight, height, distance, speed, money, lab values, et cetera) whenever possible.
Words
DO
Use words for other numbers one through ten (“We own three cars”) and 11 and up as numerals. Exception: For addresses and highways, etc., please type as they would appear in a phone book or on a map.
DON’T
"I was only going five miles an hour." Five is less than eleven, but all measurements should be numerals no matter how small. Correct: “I was only going 5 miles an hour.”
Either/Or
Do not mix numerals and words. ...