Definition:Binary Notation

Definition
Binary notation is the technique of expressing numbers in base $2$.

That is, every number $x \in \R$ is expressed in the form:
 * $\ds x = \sum_{j \mathop \in \Z} r_j 2^j$

where $\forall j \in \Z: r_j \in \set {0, 1}$.

Also see
Binary notation, like hexadecimal notation, has particular relevance in the field of computer science.