I want to be able to take a found set and within that set sum a number located within a field of all the record of that set. Is this possible? Do I need to set up a script to do this?null

Two ways to accomplish this.

You can use Summary fields. They operate on the current set of records, be that the found set while in browse mode, or a sub-summary set while in preview mode.

You can also use the normal calculation aggregate functions on a related set of records.

If you found set is based on a really complicated find, then the summary field will probably serve you best, although you may need to use some GetSummary() functions to get exactly the summarizations that you want.

If you find is simple, such as counting and totalling the invoices for a client, then the aggregate functions through a relationship is a better way to go.