Purple Math
Purplemath: Negative Exponents
This resource covers negative exponents and demonstrates how to simplify expressions containing them. Explains why "to the power zero" means "equals 1".A negative exponent just means that the base 'x' is on the wrong side of the fraction...
Science Struck
Science Struck: Adding Exponents
Explains how to add exponents as well as other aspects of exponents including positive and negative exponents, rational exponents, zero exponents, power of power, and division of exponents. Includes practice problems with answers provided.