rip off (separable): cheat; take advantage of; charge too much.
"Don't even think about buying a car there. They'll rip you off."
round off (separable): change from a fraction to the nearest whole number.
"Round all prices off to the closest whole-dollar amounts. For example, round $33.73off to $34.00."
run into (inseparable): meet by chance.
"Yesterday at the supermarket, Jan ran into her former roommate. Before yesterday, they hadn't seen each other for nearly five years."
run out of (inseparable): use the last of.
"On the way home from work, Art ran out of gas."