What are the rules for writing numbers?

Question

Like how would I write these numbers:

1 or one

10 or ten

15 or fifteen

25 or twenty-five

100 or one hundred

150 or one hundred and fifty

1,000 or one thousand

10,000 or ten thousand

etc

What are the rules that apply to numbers like those??? Do you even get what I mean??? I never have been able to remember...

THANKS

Answer 1

It varies somewhat with the context, but for general writing, the authority is the Chicago Handbook, which you should have on your desk.

http://www.amazon.com/Chicago-Manual-Sty...

(They have an online version too, but it is available only with a paid subscription.)

For this specific question, the traditional answer is here:

http://www.grammarbook.com/numbers/numbe...

My personal feeling is that if the numbers are to be compared or calculated, use digits. So in an arithmetic word problem such as "It takes five men four hours to ..."

I would tend to use digits: "It takes 5 men 4 hours to ..."

On the other hand, when talking about a trip, "The five of us hiked for three hours to the ..."

HTH.