Explore e on MathWorld

The mathematical constant denoted e is the base of the natural logarithm which has value of approximately 2.718.

E is a high school-level concept that would be first encountered in a pre-calculus course covering exponents and logarithms. It is listed in the California State Standards for Algebra II.


Irrational Number: An irrational number is a real number that cannot be written as a fraction. Irrational numbers have decimal expansions that neither terminate nor become periodic.
Natural Logarithm: The natural logarithm is the logarithm having base e.

Classroom Articles on Exponents and Logarithms

  • Exponential Function
  • Logarithm

  • Classroom Articles on Pre-Calculus (Up to High School Level)

  • Asymptote
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  • Complex Conjugate
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