Apoligies I'm still rather new and learning. My problem is I have a list of parent account with the field Funded_Deals__c and I need to find all child accounts related to their respective parent accounts, then do the sum of that field for all child accounts related to the parent account and update the parent account with that sum. I feel like the way to do this would be to have 2 lists one for parent and one for child accounts and then map the data but I need a little help figuring out exactly how to do it.