Pete,

I don't know where you play, but I've never seen a penny slot machine that actually accepted pennies. Most of them require dollar tokens or only accept cash. So when you play 1 credit and cash out, you get a 99 cent ticket. Tom's message details the rest.

I usually look for a nickel machine that takes nickels, put one in and hope it cashes out a TITO instead of giving me my nickel back.