Definition:Mantissa

Scientific Notation
Let $n$ be a number expressed in scientific notation as:
 * $n \approx m \times 10^e$

General Logarithm
Let $n \in \R$ be a positive real number such that $0 < n < 1$.

Let $n$ be presented (possibly approximated) in scientific notation as:
 * $a \times 10^d$

where $d \in \Z$ is an integer.