Good afternoon folks.

I've chosen SQL 2016 Express (I won't have more than 10 Gig's of info...) because its competent of doing math functions. I have several projects that deal with subtracting totals from a starting total, then displaying the remainder to the user (in another column). Just curious what an expert would do for setting this up logically? I've thought about making each entity it's own table or individual record so I can tie a form in to calculate the totals, sum it up then subtract from base but I'm not convinced this is efficient. Is there SQL code that could do this on one singular line? How do the experts handle running totals in general?