Help with a subtraction problem

[aherzog]

I have a column with numbers, let's say B4-B40 with the title Quantity. I now have a second column, let's say D4-D40 which has no numbers in it yet. When I enter a number in any cell in column D, I want the cell in that same row in column B to automatically update the quantity to the difference between the two numbers. For example,

B4=17
I enter 10 into D4
B4 now equals 7

I know this is so simple, I just can't remember how to do it! Thanks.

 

[Puertorekinsam]

You are going to have to do this with VBA otherwise you will wind up with a circular reference in your formula.

If I remove the 10 from D4, should the B4 return to 17?

 

[aherzog]

Yes, it should return to 17.