Anything after will be formatted as a right-aligned equation number. To insert a preset equation in Word place your cursor at insertion point in your document where you want the equation to appear. Then click the Equation button in the Symbols button group on the right end of the tab.
This tutorial demonstrates how to write a math equation using Microsoft Word 2010.
For all versions of Word then click the Formula button in the Data button group to open the Formula dialog box. Insert a formula in a table cell. Use the Formula dialog box to create your formula. A cleaner approach than using tables is just to type 1 at the end of the equation.