Currency

Based on Augustan-era Roman coins (27 BCE-301 CE)

	US dollars	Aureus	Quinarius aureus	Denarius	Sestertius	Semis	Quadrans
Aureus	$100	1	1/5	1/10	1/20	1/100	1/200
Quinarius aureus	$20	5	1	1/2	1/4	1/20	1/40
Denarius	$10	10	2	1	1/2	1/10	1/20
Sestertius	$5	20	4	2	1	1/5	1/10
Semis	$1	100	20	10	5	1	1/2
Quadrans	50¢	200	40	20	10	2	1

To denote a price, one would use the first initial of the name of the coin. In the case of Quinarius Aureus, it is QA; in the case of Sestertius and Semis, Sestertius is SE, and Semis is simply S.
For example, a price of $150 is 1A, 2QA, 1D in written form, while in spoken form, the coin names are usually said in full.