Each cloud has a small triangle with a number, called a delta. The number matches a row in the revision block of the title block.
An addendum may reissue a floor plan with three clouds. One moves a door. One changes a wall type. One adds two floor drains.
Find every cloud on every reissued sheet. Update your takeoff for each one. Then compare the full sheet against the old one, because drafters sometimes miss a cloud.
Record which revision your price includes. Put that in your proposal.