A mathematical series is the sum of a arithmetic sequence. We find the sum by adding the first and last terms, a1 and an, dividing by 2 to get the average of the two numbers, and then multiplying by the number of numbers, n: Sn = n2(a1+an). Any part of our lives can be thought of in terms of arithmetic progression or sequence. Now all we have to do is look at how we use it every day. When we know about this kind of sequence, we can see how things happen in our lives from a different point of view.