You can display a field's value as text on a page using && followed by the name of your field.
This allows you to display field values as uneditable text on a page without needing to use field controls.
For example, to display the total cost field value using a text control, you can set its text content to be:
The total cost for this order is £ &&total_cost
When the form runs, this will display as:
The total cost for this order is £ 0.00