To answer your questions, the ones I have visited have high expectations and want the children to perform on the age appropriate level but how to teach a 4th grader multiplication and division when he/she can't even count beyond 100 or can't add or subtract. As a result, the teacher has to go back to 1st grade skills so the child can get the basics mastered.
Same thing with Language arts. People stereotype deaf schools has having lower standards when they really have no idea of all the issues involved.
