When to use numerals and when to spell out words?

Sarah:

I posted this comment in the "contact us" section because it was not related to this thread (and I lost the original reference). "Contact Us" asked me to repost here:

Sarah:
Thank you for responding to my question about building an academic critique.

While perusing some of the other advice on the site I found a very thorough critique you did on someone's paper. I have a question about when to use numerals and when to spell out words. I learned that numbers greater than 10 and time (including years) use numerals.
In your advice you recommended the author change "4 years" to "four years". This is contrary to what I've learned. I would normally agree with the original author unless I was starting a sentence such as "Four years is a long time...." I would write "I went to school for 4 years." (I use The Gregg Reference Manual, 10 ed., paragraph 436, "Periods of Time". Am I misinterpreting it?)

Is there updated guidence or references that I should be following about use of numerals. (I use them A LOT!)

Thanks for helping create a great resource.
Dave

Greetings!

That's a good question! I did some checking, and according to the Publication Manual of the American Psychological Association, you are correct; while one would normally write out "four" because the rule is to write out numbers one through nine, one should say "4 years" because the number refers to a date. Here are the rules in a nutshell.

Use numbers (numerals) in these instances:

1. For all numbers 10 and above: "There were 17 students in class."
2. All numbers below 10 that are grouped in comparison to numbers 10 and above: "Ony 5 of 17 students passed the course."
3. When using numbers immediately before a unit of measure: "a 5-minute wait"
4. Numbers that represent statistical or mathematical functions or formulas: "a ratio of 12:1"
5. Numbers that represent time, dates, ages, sizes, scores, money, and points on a scale: "It happened 5 years ago"; "a roomful of 6-year-olds"; "$40."
6. Numbers that represent a place in a series: "week 7 of an 8-week diet"
7. In a list of four or more numbers: "We had 1, 2, 5, and 8 pieces, respectively"

For more complete information, you may wish to check the APA manual.

I hope this helps!

Thanks,

Sarah, EssayForum.com