From the Beagle Bros Winter 1980-81 catalog: Remember your old 15-numbered Whatchamacallit with the sliding numbers> Wait till you play with a computerized one! Completely keyboard controlled, Slippery Digits features full-color graphics and different degrees of difficulty complete with music signals when you are on the right track and disappearing numbers when you're not! Each level's scores are kept in memory so players can compare their skills. Not as easy as it might seem. Slippery digits is a proven winner for all ages!