Some just put out feed, but others like to ration for a host of reasons. But, rationing doesn't work well if you under feed and is wasteful if you over feed.
Put out 3 pounds in the morning, in the feed trays. Observe how much or how little is left a 3 or 4 in the afternoon. If there is feed left, you won't want to add to it much, if at all. Check the feed tray(s) again as they go to roost at 6:30 pm or so. Is there still feed in the trays? If so, cut back a touch. If the trays are empty, you've slightly under fed them.
Portion out as much feed in the morning feeding and in the afternoon feeding that they will consume by roosting time. THAT is how much YOUR chickens need. Let them tell you. Head's up, though. They don't always eat exactly the same amount every day and, if some are still growing or once laying commences in earnest you may find you need to ramp up the amount. Cold weather will also sometimes increase demand. Good luck.