Mental retardation is mainly manifested by varying degrees of mental retardation and social adaptation difficulties. Patients are significantly lower than healthy children of the same age in cognition, language, memory, comprehension, imagination, and movement.
Mildly affected children have slower intellectual development, speech and walking than children of the same age in preschool, and have difficulty in learning after elementary school, often failing or repeating grades, and can barely finish elementary school.
Most of them can only calculate single-digit addition and subtraction, and some of them cannot even learn simple calculations.
Most of them can only calculate single-digit addition and subtraction, and some of them can’t even learn simple calculations. Severe children have slurred pronunciation, can’t even speak, can barely count, can’t go to elementary school, and can’t take care of themselves.
Very severe children are born with physical and neurological deformities, usually cannot walk, have no language skills, can only make simple sounds, can only understand simple commands and gestures, and are completely unable to take care of themselves.