Vintage Radio Shack Monkey See Calculator Game w/ Box and Manual | eBay
Rhesus Monkeys Are Capable of Doing Simple Math | The Mary Sue
According to my calculations…. | Existential Sock Monkey
Vintage Mr. Smart Educated Monkey Mechanical Calculator Toy - Etsy
Antique "Consul" Educated Monkey, Pat'd 1916 and 1918. When you set the monkeys feet at two numbers | Estate & Personal Property Personal Property | Online Auctions | Proxibid