Basic Technical Mathematics, 11th Edition

13.4 Logarithms to the Base 10

• Common Logarithms • Antilogarithm • Calculations Using Base 10 Logarithms

In Section 13.2, we stated that a base of logarithms must be a positive number, not equal to 1. In the examples and exercises of the previous sections, we used a number of different bases. However, there are two particular bases that are especially important in many applications. They are 10 and e, where e is the irrational number approximately equal to 2.718 that we introduced in Section 12.5 and have used in the previous sections of this chapter.

Base 10 logarithms were developed for calculational purposes and were used a great deal for making calculations until the 1970s, when the modern scientific calculator became widely available. ...