Business & farm

If I input materials bought that are part of a 1099 I received under inventory or supplies I don't get the full value of that total. I can't find where to switch to the Cash method for that section. That method is what I use under my business profile section but it's not an option for the inventory section. If I list items under Supplies then it's asking for a detail of each item. Can that be put in as a total? I still don't receive the full value in the Supplies section either. I am a Remodeling Contractor and purchase items for projects that are listed on 1099s I receive.