Numbering equations in Word 2007
Microsoft Word isn’t the best software for technical writing, but sometimes we have to use it. Here is the best way I’ve found to emulate the automatic equation numbering that LaTeX has been doing for years:
Insert an equation (old-style)
Use the Object button on the Insert tab to bring up the dialog box. Choose Microsoft Equation 3.0 and enter an equation. Insert equation
Create tab stops
We’ll create two tab stops: a right tab for the equation number, and a center tab stop for the equation. Note the tab type button, which is circled in the images below. Right or left-click this button to change the tab stop type, and then click on the ruler to add a tab stop. I estimated the center of the page, but you may want to calculate exactly where the center tab should go. Insert right tab stop Insert center tab stop

Create an equation style (optional)
If you’re going to enter several equations, create an Equation style so that the tab stops will be set automatically: Create equation style
Center the equation
Put the cursor in front of the equation object, and press Tab to center it: Center the equation
Insert equation number
We’ll use sequence fields to automatically number the equations. Insert sequence field, part 1 Insert sequence field, part 2

Create a Bookmark
In order to reference the equations by number, we have to bookmark the sequence field. Click and drag to highlight the entire sequence field, and click the Bookmark button on the Insert tab: Insert bookmark
Insert cross-reference
When you want to refer to an equation number in the text, click “Cross-reference” on the Insert tab. Choose “Bookmarks” from the pull-down menu, and select the name of the equation that you just bookmarked: Insert cross reference
Add more equations
The fast way to add more equations is to copy and paste everything you just created. However, you’ll have to update the sequence field manually. Just select the sequence field and press F9 to update the number: Paste and update field
Conclusions
Word is not the best software for technical writing, but sometimes you’re stuck with it due to the requirements of advisers, collaborators, journals, etc. I think this is the best way to keep track of equation numbers automatically.
References
Instructions for using equations in older versions of Word.
Comments
Comment #1 by Roozbeh
Roozbeh - Mar 5, 2013
I have a solution for automatic numbering of equations. http://roozbeh-eng.blogspot.com/2012/12/well-this-is-my-first-post.html