Grammar: Numbers, Dollar Signs, and Percentages

I currently work for an Investment Advisory Firm here in St. George. I am the receptionist and I am often called upon to type and mail letters, or proofread things before they enter the mail to our clients. Recently my company sent out a quarterly newsletter about the Economy and everyone in the office was asked to participate and help correct. In the midst of our work, a few of my co-workers asked the question about when it was appropriate to use number, a dollar sign, or a percent sign verse spelling the out. After doing some research I now know the correct answer and will gladly share my spoils with you.

Using numbers is a pretty common and not so complex rule which most people understand on the surface.
1. Spell out the numbers one through ten. Use numeric digits for 11 and higher.
This is easy to do, but sometimes harder to remember. Make sure to reread your drafts carefully to avoid making mistakes in the future.

Expressions about money and percent usually appear in academic writing as statistics or resources. By applying the number rule to money.... add the dollar sign ($) and comma if the amount is greater than 10.
2. Use dollar signs and commas where appropriate.
The percent sign follows the same rule. If the number is greater than 10 add the percent sign (%) otherwise, it is correct to spell out "percent."
3. Use the percent symbol when using numeric digits.

If you need more clearity on the rules or just want to see examples click here.