I've have tried partial products for multiplication with one of my kids who struggles with multiplication and that worked well, so I think I will go back and try this method of addition with her as well as sometimes addition with regrouping is problematic.

It's so crazy to me because I see people blasting new math methods because they take more steps, but if you have a struggling student, sometimes the old school shortcut ways are not so intuitive or easy to understand what is going on. To me, the partial methods are easier to understand what is going on. I don't think it matters how you get the answer, just that you get it and understand what you are doing.

On a related note, I came across a PDF that shows Five Ways to Add Multi-Digit Whole Numbers.