In general, a remainder is a quantity "left over" after performing a particular algorithm. The term is most commonly used to refer to the number left over when two
integers are divided by each other in integer division.
For example, 
,
with a remainder of 6. Of course in real division, there is no such thing as a remainder
since, for example, 
.
The term remainder is also sometimes applied to the residue of a congruence.
