What must be added to five -eighths to make a whole one?

To find out what must be added to five-eighths to make a whole, you subtract five-eighths from one. A whole can be represented as eight-eighths, so you calculate: ( 1 - \frac{5}{8} = \frac{8}{8} - \frac{5}{8} = \frac{3}{8} ). Therefore, three-eighths must be added to five-eighths to make a whole one.