Use the Equation Editor in MS Word.
Insert an equation
1. Click where you want to insert the equation.
2. On the Insert menu, click Object, and then click the Create New tab.
3. In the Object type box, click Microsoft Equation 3.0.
4. Click OK.
5. Build the equation by selecting symbols from the Equation toolbar and by
typing variables and numbers. From the top row of the Equation toolbar, you
can choose from more than 150 mathematical symbols. From the bottom row,
you can choose from a variety of templates or frameworks that contain
symbols such as fractions, integrals, and summations.
If you need help, click Equation Editor Help Topics on the Help menu.
6. To return to Word, click the Word document.
Note If Microsoft Equation Editor is not available; you may need to install
it. How to install Equation Editor.