EXAMP. How much Sterling money is equivalent to 3390 pezzos 16 foldi of Genoa, exchange at 51½ d. Sterling per pezzo?

Soldi. d. Pez. foldi.
If 20 : 51½ :: 3390 16
8 20
160 415 67816
415
339080
67816
271264

d. L. s. d.
160) 28143640 (175897½ = 732 18 ½

If Sterling money be given, it may be reduced or changed into pezzos of Genoa, by reversing the former operation.

Exchange money is reduced to lire-money, by being multiplied by 5½, as follows:

Pez. foldi. Decimally.
3390 16 3390.8
5½ 5.75
16954 0 169540
½ = 1695 8 237356
¼ = 847 14 169540

Lires 19497 2 Lires 19497.100
And lire-money is reduced to exchange-money by dividing it by 5½.

In Milan, 1 crown = 80
In Naples, 1 ducat = 86
In Leghorn, 1 piastra = 20
In Sicily, 1 crown = 127½
12 Denari make 1 foldi s. d.
20 Soldi make 1 piastra = 4 6 Ster.

Books and accounts are kept in piastres, foldi, and denari. The piastra here consists of 6 lires, and the lire contains 20 foldi, and the foldi 12 denari, and consequently exchange money is 6 times better than lire money. The course of exchange is from 47 d. to 58 d. Sterling per piastra.