Students learn the product rule, which states that when multiplying two powers that have the same base, add the exponents. For example, x^4 times x^3 = x^7. To multiply 6s^3 times 3s^6, multiply the coefficients and add the exponents, to get 18s^9. If there is no exponent on the variable, it can be given an exponent of 1. For example, x can be thought of as x^1.