I’d like to ask the good people of this community that, if you do know the solution or figure it out, that you not share the answer here. Feel free to announce your success, but there’s something to be said for discovering the answer completely unaided, even if it takes years.
It’s embarrassingly obvious once you see it though.
You add the two digits in the left bubble together. You separate the digits in the right bubble. You now have three separate numbers that when added together created the bubble for the next layer down
You should wrap this in a spoiler tag.
Thank you