How do I work with log base e on a calculator?

##log_e = ln## Just use the ##ln## button

it called the natural log and is written differently, If you are using a calculator you use ##ln## when the base of a ##log## is ##e##.

Another example is, when the base of a log is 10 , ##log_10## in math we just write ##log##, and it is known that the base is 10. If the base is any other number then you need to write the base. This is of course unless your teacher says to still write the base 10. But, thats another story.

When you use or ##ln## you will usually always need to use a calculator if you want an exact number, unless something cancels out.

Remember, ##log## or ##ln## is asking to what power do you take the base to get the number in front of log. ##log_10 100 = ?## 10 to what power equals 100?

10 to the 2nd power, ##10^2##

so the answer is 2!

##log_10 100 = 2##