Sounds like you have placed the summary field in the body of your layout and that you are viewing it in List View. If you add a trailing grand summary part (see Part set up... for a way to add or delete layout parts), you can place the summary field in that layout part and see it just once immediately after the last record listed in the body.
You may find this tutorial thread on summary fields useful: Creating Filemaker Pro summary reports--Tutorial
In list view - list all records in a list, will display the fields in the body for each record. You will need to setup another part (Sub-summary) under Layout, Part setup. Footer display at the bottom of the page where a sub-summary get be at the top or bottom of a category.