Microsoft Access 2000 formula question

[Kathy S]

I need to do a simple match query in my database and I have not been able to
figure out how to do it.

I have:

Column a
Column b
Column c
Column d

Each column has positive currency dollars in it. I want to add Col a and
Col b and subtract Col C and post the answer in Column d. Can anyone help?

 

[Allen Browne]

See:
Calculated fields
at:
http://allenbrowne.com/casu-14.html

The article explains how, and more importantly when, to store calculated
totals.