The primary motivation is to find something to assist a young school student with fine motor problems, better do his mathematics schoolwork.

He can't do any written working with pen and paper. He can type (slowly and clumsily) which allows him to do written work in many subjects but much arithmetical working typically involves noting steps down, crossing things out, rearranging terms etc. This is difficult to record via a keyboard. Even more difficult for someone with fine motor problems.

As a consequence he has to either try and direct an assistant to write his working steps or he has to do many steps it in his head which make it hard to follow his working (and results in errors). It also makes it hard to learn arithmetic techniques that use written steps.

The idea may not prove to be of much value but I think it is worth exploring.