Can anyone help me about my other problem about excel?
I'm trying to create a simple inventory system using microsoft excel 2010, and i have a sheets naming stocks & sales. i want to make it automatically subtract the value from the sheet(stocks) when i input the quantity of that said product inside the sheet(sales).
thanks for your help! :)

Reference the sheet named sales in the formula for the cell in your sheet named stock, so:

eg. =F16-'sales'.F16 or =F16-'sales'.C16
Consider arrays.eg {B3:B10-'sales'.B3:B10}