I am running a decreasing balance in a column. It is a chart tracking 12
months top to bottom. I have the functions set as such. For Example, in CELL
D11, I have the following function: =IF(D10="","",D9-D10).
I used "" because D10 has a function in it. So I only want excel to do the
math if D10 actually has a number in it, even if that number is zero. The
IF function noted above repeats down the column 12 times. Lets say in May
when I enter data elsewhere, D10 gets a value from ITS function and then D11
gets a value from ITS function. All the cells below D11 show "" (appear
empty).

NOW here's what I can't figure out. How can I get the current lowest value
in the column to display in a cell at the bottom of the chart (say D36).
I've tried =(D11-D13-D15-D17.......) But Excel has trouble with all the cells
that don't have actual numbers in them yet and returns #VALUE.
How can I tell it to run a subtraction function using only the cells with
actual numbers in them and ignore cells that have only unrealized formulas?
Or is there another way to approach this.