Most cats have 5 toes on their front paws and 4 on the back. But there are some cats that have more than 5 toes on their front paws.
They are known as polydactyl. Though rare, these cats have been around for hundreds of years. Throughout history, polydactyls were working cats. They were usually found on ships as their extra toes made them excellent climbers and superb mousers. These cats were prized by sailors as they also tended to be quit social so they provided excellent companionship to sailors on long voyages.
The American novelist, Ernest Hemingway had a polydactyl. During his life time bouts with depression and alcoholism, his cat, Snow White was a constant companion and help keep Ernest grounded. 
Snow White often provided a calming effect on Hemingway as he wrote his novels.
At his death, Hemingway left his estate in Key West, to a trust to care for the cats he came to love. The Hemingway Home is still a sanctuary to decedents of Snow White. The estate is still maintained primarily for the benefit of a large clowter of cats – many of them polydactyls. More information at https://www.hemingwayhome.com/pilar/
