'Twenty' in the Bible

On the twenty-fourth day of the eleventh month, the month Shebat, in the second year of Darius, the word of the Lord came to Zechariah, the son of Berechiah, the son of Iddo the prophet, saying,

And he said to me, What do you see? And I said, A roll going through the air; it is twenty cubits long and ten cubits wide.