'Twenty' in the Bible

And thy estimation shall be of the male from twenty years old even unto sixty years old, even thy estimation shall be fifty shekels of silver, after the shekel of the sanctuary.

And if it be from five years old even unto twenty years old, then thy estimation shall be of the male twenty shekels, and for the female ten shekels.

And all thy estimations shall be according to the shekel of the sanctuary: twenty gerahs shall be the shekel.