the sum of first natural numbers. Can you relate these answers to any of the known formula? . The sum of first n natural numbers are also called Triangular Numbers because they form triangle shapes.
. The sum of squares of first n natural numbers are also called Square Pyramidal Numbers because they form pyramid shapes with square base. Thinking Corner . How many squares are there in a standard chess board?
. How many rectangles are there in a standard chess board? Here is a summary of list of some useful summation formulae which we discussed. These formulae are used in solving summation problems with finite terms.