I have a lists of items in rows 1 through 22. Each item is listed individually and has a 1 in the quantity. When I total the column using the sum function I get the correct total of 22. However, if I want to subtract the item in row 10 by entering a -1 the sum, which should be 21, shows as 20. I tried different formats and nothing changed. When I entered -.5 into row 10, the sum did show as 21. I entered -.75 and the sum returned was again, 20. It appears the negative number is being doubled. What am I missing?