# Decimal Expansion

The decimal expansion of a number is the usual "base 10" representation of a real number.

Decimal expansion is an elementary-school-level concept. It is listed in the California State Standards for Grade 2.

### Prerequisites

Base: | (1) In a number of system, the base is the number of distinct digits used to represent numbers. (2) In a logarithm, the base is the number with respect to which the power operation is inverted to form the logarithm. (3) In a geometric figure, the term base is used to refer to the bottom edge or surface. |