grand total calculation

I Trying to calculate a grand total from the items price in a list view. I already have it set up so the price is entered on one screen and then saved and displayed on a different screen. The problem I'm running into is that I am unable to have the ability for the prices to be gathered and then displayed added up so if the price of an item is 1 and the price of a different item is 2 then the grand total should be 3.   I'm very new to this and would like some help   domain model this is the cart page (i wanted the button to be in the top right of the page but it keeps giving me an error) This is the check out page the grand total in this page is under the car items section in the domain model this is the microflow I have right now which will only calculate one of the items and not all of them. i have gone through the rapid dev course and i still need some help.
1 answers

Check if the other "cartitems" are committed to the DB, and if they get retrieved, try to duplicate the retrieve action or remove the aggregate action and check if the full list is being retrieved by adding a breakpoint and checking the variables window.