simply 2012 canadian edition

is there a way I could put a new colum after the colum where I can see what I sold.  Here's my problem,  let's say I sold 20 sandwiches, and I get 4 back cause the date is not good anymore, so I would like to see on the same line that I have sold  20 sandwiches, next to it 4 got returned back so I can see that I have a 20% of return of that kind of sandwich.  Right now I can see all of what I sold, and under I can see the returns, but I have over 200 products, so I have to go down the page, see  how many got return and go back up and see how much I sold and then I can calculate my return %......takes a lot of time, thanks for the help!