I am working on a Stock Control Database. The data is held in a number of tables one of which has separate fields to cover the Opening Qty, Additions, Subtractions and Adjustments. This table is accessed through a subform from one of the main forms. Each item is displayed (page at a time) with the subform showing all the transactions for that item. I would like to show the up-to-date stock quantity i.e. the totals from the subform where the stock quantity = Opening Qty + Additions - Subtractions for that item only.

Problem 1: I can’t get to sum all transactions for that individual item only.
Problem 2: Assuming I get that sorted out - where and how do I do the calculations on these totals to get a final balance i.e. opening stock + additions – subtractions for that item.

I except that this might be an involved question but pointers would be appreciated

The structure of your table is unclear but it sounds like your design is poor. You realy need to normalise your tables. It would be better to have a table that had separate records for each transaction, not fields. If the sign of these records was correct, then you could add a simple total to your subform or run a totals query to generate your current balance.

In addition, you should not be basing your form on the table, but on a query. This way, you can do calculations, apply sorting and all manner of manipulations to your data which you can't do if the form looks directly at the table.