How to subtract a specific value from one cell when data is added into another?

[vxtrme2]

Hey guys,

So this needs a little explaining. Basically I finished a stock take for my business and want to be able to easily record how much of something is used to keep an accurate count. I have 3 columns stating the current gross amount in ml's, how many drops that is and the required amount for the product. Now I have a whole list of ingredients that go into making the product and was wondering if its possible to have another cell titled 'Total Batches Made' in that when I enter say the value 2 into this cell, it will automatically subtract 10 (required amount used from that ingredient) from the gross cell. This way if I make say 10 batches my stocktake levels will be always up to date.

The only problem I see with this is that the gross cell has to show a certain value at all times so I can see how much I have, but then behind the scenes needs a formula to be able to subtract the amount that is used from the required cell when I have completed a batch. Hope this makes sense!

Gross TotalDrops Required
12 240 5

[ufopilot]

Attachment 381149this may get you started
Autofill the formula down in column D ( you can hide column D)

[vxtrme2]

Awesome ufopilot you legend thats exactly what I'm after. Thanks heaps!!