Wow. I’ve never had to post before, as the hints and/or forum discussion always got me through each page. This one, however, has me stalled.
I’ve got the hints and have a numerical framework for the upper figure. I can’t get the lower figure to reconcile unless I use subtraction as an operation (as opposed to addition in the upper figure). The page also implies that the answer is a 4 digit number, but can’t figure out how you get 4 numbers with only 2 question marks.