Summation is the addition
of a set of numbers; the result is their sum or total. An interim or present total of a summation process is
termed the running total. The "numbers" to be summed may be natural numbers, complex numbers, matrices, or still
more complicated objects. An infinite sum is a subtle procedure known as a series. Note that the term summation
has a special meaning in the context of divergent series related to extrapolation.
Summations are often used in the process of reducing
complex equations in to smaller factors that can be more easily manipulated for operations in calculus and other