We have a 'fifty-fifty' chance of succeeding. [=we are as likely to succeed as we are to fail]
The bill for dinner came to $43, and she gave him a 'fifty'.
They divided/split the expenses 'fifty-fifty'. [='equally']
(..) You don't like the game! It ain't fair. I don't operate that way. Are you a bookmaker or an investment counselor? - It's your bananas. How much? - Fifty thousand. - Fifty thousand! - It's your figures I'm balancin'. I've seen nuts before, but you've got watermelons. (..)1974 The Gambler
(..) a family of five. At , he opened a furniture store. Which he built into two, then fifteen... then fifty, then a hundred. Until finally he had the largest chain America had ever seen. But no matter where he went... or what he did... he always found a place for every (..)1974 The Gambler