'Fifth' in the Bible

He shall make restitution for that which he has sinned against the holy thing, and shall add to it a fifth part of it and give it to the priest. The priest shall then make atonement for him with the ram of the guilt offering, and it will be forgiven him.

In the fifth year you are to eat of its fruit, that its yield may increase for you; I am the Lord your God.

But if a man eats a holy gift unintentionally, then he shall add to it a fifth of it and shall give the holy gift to the priest.