K.D.
I don't know of any tutor, but when I was in grade school we had a ruler taped to the top of our desk and that was how we were taught to add and subtract. We would put our finger on the first number, for example 5, and if we needed to add 2 the teacher told us to move our finger up two spaces to 7. This is how I taught my daughter to add and subtract. Visualizing addition and subtraction may help her. Good Luck!