Display equations and equation numbers are out of position after re-configuring document

There are several scenarios that could result in this issue. Here are 2 examples:

1. You originally had a document configured for a 2-column layout, and subsequently changed it to a 1-column layout. You noticed after the change, the display equations are no longer centered and the equation numbers that had been nicely-aligned at the right margin are now positioned far inside the right margin.
2. After writing an article configured for U.S. letter-sized paper (8½x11 inches), you remember that since your colleagues are located in Europe, their style guide requires A4 paper (210x297mm -- approximately 8.3x11.7 inches). After changing your document layout to A4, you notice all the equation numbers are positioned beyond the right margin, and the display equations aren't centered.

Equation numbers are formatted, and the numbers and equations are both positioned with a style named MTDisplayEquation. The specifications of this style's formatting are determined when you insert the first display equation into the document, whether the equation is numbered or not. Display equations are centered with a tab set at halfway between left and right margins. Right-justified equation numbers are positioned at the right margin with a right-justified tab. Therefore, making any change that affects margin settings -- such as in the 2 examples above -- will cause display equations to no longer be centered and equation numbers to no longer be positioned at the right (or left) margin.

To resolve this issue, it's necessary to first locate the MTDisplayEquation style, then to modify it.

1. The MTDisplayEquation style is not included by default on Word's Style Gallery, nor does it exist before you insert a display equation into the current document. (If you're using Word for Mac, skip to step 3.)
2. To find the MTDisplayEquation style on Windows, click the dialog launcher at the lower corner of the Styles group of the Home tab: . When you do that, you'll see the MTDisplayEquation style at or near the top of the Styles panel (screen shot on left below). If you hover the mouse over that style, you'll see a summary of the style definition. (You may also see the MTEquationSection style; we recommend leaving that one alone.) Skip to the next section.
3. If you're using Word 2011 on Mac, click the Manage styles icon on Word's Home tab: . If you're using Word 2016 on Mac, click the Styles Pane button on Word's Home tab: . When you do that, you'll see the MTDisplayEquation style at or near the top of the Styles panel (screen shot on the right below). If you hover the mouse over that style, you'll see a summary of the style definition. (You may also see the MTEquationSection style; we recommend leaving that one alone.)

Styles pane in Word 2016 for Windows. Similar appearance in other versions of Word for Windows.	Styles pane in Word 2016 for Mac.

As we mentioned earlier, MathType controls the positioning of display equations and their equation numbers with tabs. Here's how to change the tab settings…

1. Click the downward-pointing triangle to the right of the MTDisplayEquation label, then Modify ("Modify Style..." on the Mac), and you'll have an opportunity to change the style's definition. You can also choose whether you want to apply specific fonts and styling to the equation numbers within your document. Note that any styling changes (fonts, color, etc.) will affect only the equation numbers. The equation itself is not affected, nor are equation references.
2. Click the Format button in the lower left of the Modify Styles dialog, and select Tabs.
3. Adjust the tab settings to account for your new margin settings or column layout.
   
   For example, let's say you're using U.S. Letter size paper (8½x11") and your margins are set to 1" left and right in a 1-column document. Now you decide to switch to a 2-column layout with the standard spacing between columns (0.5"). When you open the Tabs dialog as described in step 3, you'll see the tabs are set for a Center tab at 3.25" and a Right tab at 6.5". Click Clear All. The width of the new columns is 3", so type 1.5" in the entry box, click the Center radio button, and click Set. Follow the same process to set a Right tab at 3".
4. Subsequent display equations and equation numbers will be positioned according to the tabs you set in step 3. Note that these settings will apply to this document only unless you click the radio button labeled New documents based on this template (Add to template on the Mac) before you click OK in the Modify Style dialog. Note also that depending on your Word Options, when you close Word, you may get asked a question to the effect that "Changes were made to the normal template, Normal.dotm. Would you like to save the changes to this template?" You must answer Yes to this question or you'll have to go through this process again.

We hope this has been helpful. As always, please let us know if you have questions about this, or if you have additional techniques that work. We'd love to hear from you.