[Blindmath] Math help

[Margaret Allen]

Hello, I am having a very difficult time figuring out how best to teach my 3rd grader math using the nemeth code.  He is at about the 2nd grade math level.  He is able to set up and add and subtract simple problems on the brailler.  My problem is once he starts borrowing and carrying it becomes so hard with all the Nemeth signs.  I am thinking of using the abacus, but as I am learning how to use it for indirect borrowing, it seems very complicated and I am not sure my little guy can handle that concept.  He has VERY limited vision, so I don't want to use a CCTV. Any suggestions?