In this lesson I will teach you about natural logarithms. A natural logarithm is a log that has a base of “e” – the natural base e. Of course if you have not watched the lesson on the natural base e now is a good time to stop and review that topic. All the properties of logarithms that we learned in the chapter will apply to natural logs as well. The main difference between natural logs and common logarithms is the notation we use to write them. We use “ln” to write a natural log rather than the notation “log”. If you look on your calculator you will see two buttons “log” and “ln”. The LOG button is for common logarithms those with base 10 and the LN button is for natural logarithms those with base e. Because natural logarithms are so widely used in science and statistical modeling we have separate notation and calculator functions- making the life of mathematicians easier. Indeed natural logs are important so study hard and practice.