This they shall give, every one that passes among them that are numbered, half a shekel after the shekel of the sanctuary: (a shekel is twenty gerahs:) a half shekel shall be the offering of the LORD.
All Commentaries on Exodus 30:13 Go To Exodus 30
Richard Challoner
AD 1781
Half a sicle: A sicle or shekel of silver, (which was also called a stater,) according to the standard or weight of the sanctuary, which was the most just and exact, was half an ounce of silver, that is, about half a crown of English money. The obol, or gerah, was about three halfpence.