Record any increases of one cell into one cell and any decreases into another

I have a worksheet that labor is tracked on. Once a job is done, the labor comes off. When we accept a new job, labor gets added. When these changes occur, they affect a summed total. If that number increases, I want to take the increase and put it in a cell. When it increases again, I want that increases added to the number already sitting in that cell. I want to do the same with decreases to the number, but they will go into a separate cell. So, there will be one cell for increases, and one for decreases. This is only part of my dilemma.