One solution, if you don't have many negative numbers, is to add a right parenthesis to the positive numbers and then format it as white text. It will take space in the document, but be invisible on the printout.
If you have many such numbers, however, then you should consider adding decimal tabs to the column. Follow these steps:
- Select the column containing the numbers.
- Make sure the column is left justified. (Display the Home tab of the ribbon and, in the Paragraph group, click the Align Text Left tool.)
- Click on the tab indicator at the left side of the ruler until you see the symbol for a decimal tab. (It is the only symbol that has a decimal point in it.)
- Drag the decimal tab to the desired position on the ruler.
That's it; the numbers will now align in the column. Noe, there is no need for a decimal point for this to work. (Whole numbers have no decimal points.) Word still aligns the numbers correctly, assuming the existence of an implied decimal point. It even recognizes parentheses around a number as a negative sign and aligns the numbers accordingly.