Section 11-5 Common Logarithms Logarithms with base 10 are called common logarithms. You can easily find the common logarithms of integral powers of 10. A common logarithm is made up of two parts. Common Logarithm logarithms that use ten as the base Characteristic the exponent of 10 that is used to write the number in scientific notation Mantissa the common logarithm of a number between 1 and 10 Mantissa Characteristic Is 6 Given that log 5 = , evaluate each logarithm. a. log 50,000 b. log 0.005 Evaluate Change of Base Formula Find the value Using the change of base formula Antilogarithm written antilog a log x = 1.95 Use antilog to solve for x Solve