Series is the sum of the terms of a sequence. The operation of getting this sum is called summation. A series can be represented in a compact form, called summation notation or sigma notation. The Greek capital letter sigma, 
, is used to indicate a sum. In this post, Mr. Frederick Koh shares an example of a task involving summation which he believes can help advanced level students appreciate summation notation. Mr. Koh says:
Many students get thoroughly irked by the sigma notation and reconciling it properly with the notion of mathematical sequences, so I shall put forth a detailed worked example to demonstrate how one must be flexible in obtaining the required solutions.
Frederick Koh is a teacher residing in Singapore who specialises in teaching the A level maths curriculum. He has accumulated more than a decade of tutoring experience and loves to share his passion for mathematics on his personal site www.whitegroupmaths.com .
Mr. Koh is also the author of the following posts:
A challenging complex number problem with solution
Differentiation in parametric context with solution
Hi, I am an elementary public school teacher here in cavite, I am interested in number, i would like know about the mathematical investigations, and i am asking if you have a samples for such nmbr investigation?