# Natural Base e

This section has the following videos:

• Lesson Video
• Example Set A Practice Problems (Video Solutions)
• Example Set B Practice Problems (Video Solutions)
• Example Set C Practice Problems (Video Solutions)
• Example Set D Practice Problems (Video Solutions)

In this lesson I will teach you about the natural base e.  Recall that a power is comprised of a base and an exponent.  For example in the power “10 squared”  10 is the base and 2 is the exponent.  So in this lesson we will look at a special number that is used as a base with respect to powers and logarithms.  The number is represented by the variable “e” and has a value of a little of over 2.7.  The reason we use the variable “e” to represent the value is that Euler (a famous mathematician) founded the number.  What makes the value of e so important is it has amazing accuracy to mathematically model a situation.  The reason we call it the “natural” base e is the situations that the base helps us model are things like population growth or radio active decay- naturally occurring events.  As you will see this lesson will also tie into our study of natural logs- logarithms that have the number e as it’s base.  Just to be clear you will need a scientific calculator to explore and learn the topic.