What is e?

π, or pi, is an irrational number that we use in a lot of areas of math
Pi is actually a never-ending, never-repeating decimal, but we usually use 3.14 to approximate it
'≈' means 'approximately equal to'
'e' is also an irrational number, so it also goes on and on forever without repeating
We can approximate 'e' to 2.71828
'e' is used so often as a base in exponential expressions that we call it the 'natural base'

1. We use the irrational number π, or pi, so often that it gets a special name
2. There is another irrational number that we also use so much that we give it a special name -- we call it 'e'
1. Just like pi, 'e' is a never-ending, never-repeating decimal
2. But we usually approximate it to about 2.71828
3. So 'e' is actually a number, NOT a variable
1. Since 'e' is a decimal that goes on and on and never repeats, it is an irrational number
1. We use 'e' so often as the base for exponential expressions that we call it the 'natural base'
2. An exponential function with 'e' as its base is called a natural base exponential function
1. 'e' has a lot of useful applications to real world problems

What is the natural base e?