Math SAT 1:1 tutor in Plano, Texas

I am looking some SAT 1:1 tutor in plano/Frisco/Carollton Texas. Primarily for math.
I prefer not KD and big servics. Somebody who had good success with 1:1 math tutoring.
My son does reasonably well with concepts. But slow or taking time to apply, and makes mistakes.
Looking for some good (or who had good success) math tutor, help to identify his mistakes and further improve.
Any suggestions?