Having a cell subtract from another cell and then erase contents after

Hello

Will someone please help me out? I am trying to have a cell subtract a cell from another cell and entering the result into a different box but is there a way to have it erase the contents from that box once it subtracts it? That probably doesn't make much sense so here's an example. It's an inventory sheet I am working on.

Example: In cell H4 when I type a number to subtract it enters the result into cell
M4 I have the formula =SUM(G4,-I4,)
so then it calculates into cell M4 Is there a way to have it erase or change the number I entered into cell H4 to 0 after it subtracts it ?

Hard to see the sense of removing the value once subtracted. (Assuming your formula in M4 actually refers to H4 and not I4!)

Before erasing:
G4 = 10
H4 = 7
M4 = 3

After erasing:
G4 = 10
H4 = 0
M4 = 10

So what is the value of entering a value in H4?

g

Let me try to clear this up. G4 is the stock on hand. Subtract H4 from G4, H4 is the amount used in one day. We want the sum of this(G4-H4=M4) M4 to appear as the new stock on hand and replace G4 with M4 and clear or zero out the H4 & M4 cells. Then the new stock on hand total is the only cell that remains visible.