A learning disability is a disorder that affects one or more basic psychological processes involved in understanding or using spoken or written language. It can cause difficulties with listening, thinking, reading, writing, spelling, or math calculations. Learning disabilities are intrinsic to the individual and presumed to be caused by central nervous system dysfunction. Children with learning disabilities may have problems with oral expression, listening comprehension, reading skills, reading comprehension, math calculations, or math reasoning. Educational programs for learning disabled children use behavioral, cognitive, medical, multisensory, and direct instruction approaches.