When multiplying exponents, remember the first rule: when multiplying similar bases, add powers together. 52% + 56% =? The bases of the equation remain unchanged, while the exponents' values are added together. Adding the exponents is only a quick way to get at the answer. Simply add the exponents to multiply exponential expressions with the same base. Simplify. The product rule applies because the base of both exponents is a. With a common basis, add the exponents.