Expanded notation is the term given in elementary mathematics education for the expansion of a positive integer in the form 
, i.e., as a sum of appropriate
powers of 10 (the base of the
expansion) times its digits (in the case of base-10,
decimal digits). For example, the number
with decimal expansion 1234 would be written
in expanded form as
 |
Negative 
are also allowed in expanded notation of arbitrary (not necessarily
integer) numbers, e.g.,
 |
but such expansions are usually not considered or deferred in elementary education contexts.
The same place-value principle gives a binary expansion, using binary digits and powers of 2.
