Select the equation you want to add. To obtain the math environment click on Equation on the Insert ribbon on Windows or Word for Mac 16 or in Document Elements on Word for Mac 11. Choose Insert Equation and select Insert New Equation from the bottom of the built in equation gallery.
Under Equation Tools on the Design tab in the Structures group click the Limit and Log drop-down list.
Select the Insert tab on the ribbon. This tutorial demonstrates how to write a math equation using Microsoft Word 2010. Everything you type in this environment is considered math. Find the Equation icon p.