What is the numerical value of e?

Answer 1

The exact value of 'e' can never be written with numbers, which is a big part of
the reason why scientists and engineers always use a symbol ( e ) to refer to it.
Just like 'pi', you can have a lot fun talking about millions and billions and trillions
of decimal places, none of which means anything.

An approximate value for 'e' is
2.718281828459045 .
However, I can tell you ... speaking as an engineer ... that if you use ' 2.72 ' for 'e',
then your work is wrong by only 0.06 percent, which is usually more than fine.