A cleaner approach than using tables is just to type 1 at the end of the equation. From the top menu select Insert Object Create New. Type the left bracket that you want to appear around the equation number.
On the Layout tab under Table Tools click Formula.
Calculations in the table 1. Click the table cell where you want your result to appear. Position the insertion point in the right-hand column then click on the Align Right tool on the formatting toolbar. This will bring up the Formula dialog with a default of SUM LEFT.