Type an equals sign the SUM function and the numbers you are adding surrounded by parenthesis. This tutorial demonstrates how to write a math equation using Microsoft Word 2010. To do this click inside the last cell in the fourth column click on Layout in the ribbon and then click on Formula at the far right.
A dialog named Formula is displayed typing SUMLEFT in the formula text box.
Under Formula Word takes a guess as to the formula you might want to use and displays SUM LEFT. You can click Write button and use your mouse or writing pad to write the formula here. Another way to derive this formula is to let S Sum from k to n of i write this sum in two ways add the equations and finally divide both sides by 2. Often mathematical formulae require the addition of many variables Summation or sigma notation is a convenient and simple form of shorthand used to give a concise expression for a sum of the values of a variable.