I know I’m not the only one that has struggled to remember the rules regarding when to write 3 or three in an essay. Fortunately, I will be clarifying the rules so that next time you run into this issue, you will remember what to do. Here are some brief rules to follow.
1. The most commonly known rule is that if the number is less than 10, you must use the actual word (one, two, three, etc.). Additionally, if the number is greater than 10, you should use the numerals. However, you may choose to use words for numbers that are higher than ten and can be said in no more than two words. It is a matter of personal choice, but either way is accepted.
Example 1: All of the thirty-nine students attended math class yesterday.
All of the 39 students attended math class yesterday.
Example 2: There are 178 children enrolled for the summer cheerleading camp.
Incorrect: There are one hundred seventy-eight children enrolled for the summer cheerleading camp.
2. Always use words for numbers that are at the beginning of a sentence. If possible, re-word the sentence so that a long number is not at the beginning.
Example 1: Eight hundred fifty animals were rescued last year by the new wildlife preservation organization.
Example 2 (revised): The new wildlife preservation organization rescued 850 animals last year.
3. Numbers within the same categories should show consistency.
Example: The woman bought 30 dollars worth of lottery tickets from five different stores. She previously won 100 dollars from purchasing tickets from two different stores.
Incorrect: I have 20 pairs of shoes, but nine of them are too small for me now.
In the incorrect example, I should have either spelled out twenty or written the number 9 in order to make them consistent.
4. Spell out shorter versions of decades in lower-case letters. Or, put an apostrophe before the number and not before the s.
Example 1: I was born in the seventies (or '70s), and my parents were born in the forties (or '40s).
Incorrect: I was born in the ‘70’s, and my parents were born in the ‘40’s.
Example 2: I was born in the 1970s (or 1970’s), and my parents were born in the 1940s (or 1940’s).
5. The time of day can be written either as the number (using a.m. or p.m.) or written out (using o’clock). However, when you are expressing 12:00 a.m., use the word midnight instead. Also, use the word noon in place of 12:00 p.m.
For more tips on writing numbers in an essay, visit Daily Writing Tips.