The 'Negative Exponent' rule isn't difficult to use, but it's a little unusual. Let's start with this example, that doesn't use any exponent rules, just simple powers: By writing out all the 3's and reducing the fraction, only a '1' remains on top, but two 3's are clearly left behind on the bottom. Now let's do the same question using the Quotient Rule: (subtract the exponents) We have just done the same question two different ways, and come up with different answers. Since the question was the same each time, the answers must be identical. This means that: Here you see the negative exponent rule illustrated. When there is a negative number for an exponent, the answer isn't negative at all; it's a fraction! You can think of the negative sign in an exponent as really meaning "one over", with the actual question appearing on the bottom of the subsequent fraction. Here's another one: According to the rule, it should equal: The Negative Exponent Rule says: "A negative exponent can be replaced by 'one over', and the rest of the question goes on the bottom of the fraction" Here's one more example: Powers Introduction Simple Powers | Product Rule | Quotient Rule | Power Rule Zero Exponent | Negative Exponents Main Page