The number e , sometimes called the natural number, or Euler’s number, is an important mathematical constant approximately equal to 2.71828. When used as the base for a logarithm, the corresponding logarithm is called the natural logarithm, and is written as ln(x) ⁡ . Note that ln(e)=1 ⁡ and that ln(1)=0 ⁡ .

What does the weird e mean in algebra?

It’s the Greek capital letter Σ sigma. Roughly equivalent to our ‘S’. It stands for ‘sum’.

What does the € mean in math?

∈ (mathematics) means that it is an element in the set of… For eg x ∈ ℕ denotes that x is within the set of natural numbers. The relation “is an element of”, also called set membership, is denoted by the symbol “∈”.

On a calculator display, E (or e) stands for exponent of 10, and it’s always followed by another number, which is the value of the exponent. For example, a calculator would show the number 25 trillion as either 2.5E13 or 2.5e13. In other words, E (or e) is a short form for scientific notation.