Looking for a calculator that looks like a phone? The Mobile Calculator claims to be such a thing.
Well, at least in the eyes of designer Naori Miyazaki, I don't recall seeing a mobile quite so tall and thin, but I'll run with it. Expect all the essential calculating features of a calculator, along with a built-in clock (12/24 hour), a durable ABS casing and a pouch for keeping it safe.
Al that for $28 (around £15).