<i>We won over two hundred dollars?more than enough to get home <u><b>on</b></u>?with our second quarter in the slot machine.</i><br/><br/>Why do we have 'on' here? What does it imply? Is this 'on' really necessary?<br/><br/>Is the 'on' in question semantically the same as this one?<br/><br/><i>Cars run <b>on</b> leaded gas these days.</i>