At least you didn't say "scoops" or "handfuls" and cups are a common kitchen measurement.
The crumbles that I feed (not Layena) weigh about 1/3 pound per cup. So, if your feed is comparable: you are giving 3 adult-size chickens, 1 1/3 pounds of feed each day.
I will say that along with "free range . . . kitchen scraps, scratch" it seems more than enough. Depends on how much of those treats they are getting. By itself, I think that you are giving enough commercial feed for 3 or 4 chickens of most dual-purpose breeds.
Steve