You can setup your form to calculate the total amount for the products selected by the users. Please note that we do not have the option to calculate the total for specific products only.

You have added required fields in the first page along with the quick navigation option for categories. This set up allows users to select a category and directly go to that category page without filling the required fields in the first page. Users will be able to submit their order without filling in all the necessary details. So the responses may not be recorded properly. You should move the required fields after the category pages or remove the quick navigation from the first page.

no, the form is design to be like that, in the first section they have to fill all their foods. and calculate the foods. and then we ask do you want to buy snacks? if their answer is no, the bill calculate only for foods, but when jt say yes, the bill calculate for snack only. how to do that?

or at least, i have total from foods only, so its okay, when the snacks bill include the foods, but i can substracted the amount of total bill - total foods only = total snacks

You can only calculate the total amount for the products ordered by the user. We do not have the option to calculate separate totals for specific products.