3 segregated groups of Arab and Jewish deaf children of CA 10;9 (n = 28) were compared with a group of hearing Arab first graders (CA = 6;10, n = 32) on tests of basic arithmetic, static balance control, and the ability to suppress synkinetic finger movements. The hearing-impaired performed as well on arithmetic tasks and on the tests of synkinetic control as their normal peers who were four years younger, while on static balance they were even inferior to the latter. Significant correlations were found between the basic arithmetic and motor skills, within the hearing as well as within the hearing-impaired groups; these remained significant even within the small subgroups of the latter. As these results cannot be accounted for by low intelligence and neurological disturbances, or by direct or indirect effects of deficient language development, the assumption is supported that some type of neurological immaturity, unrelated to hearing loss, interferes with the acquisition of numerical skills in deaf children.