ok , u can use bistables to do it ,its very simple , look at the pics , it uses 4 jk bistables to get ur number into 4 digit , then u can use any transcoder to get it working on a 7 segment.
i'm joining here also the 74ls192 (an up down counter ) datasheet .
if u need anything else just tell me and i'll try to make complete schematics for u (when i have some free time ). but i think if u search for it u will find what u want .