farthing, which is marked thus, ¼, being one fourth of a penny.
| 2 | farthings are | 1 halfpenny | ½ d . |
|---|---|---|---|
| 2 | halfpence | 1 penny | 1 d . |
| 12 | pence | 1 shilling | 1 s . |
| 20 | shillings | 1 pound [42] or sovereign | £1 |
| 21 | shillings | 1 guinea . [43] |
- When any quantity is made up of several others, expressed in different units, such as £1. 14. 6, or 2cwt. 1qr. 3lbs., it is called a compound quantity. From these tables it is evident that any compound quantity of any substance can be measured in several different ways. For example, the sum of money which we call five pounds four shillings is also 104 shillings, or 1248 pence, or 4992 farthings. It is easy to reduce any quantity from one of these measurements to another; and the following examples will be sufficient to shew how to apply the same process, usually called Reduction, to all sorts of quantities.
I. How many farthings are there in £18. 12. 6¾?10
Since there are 20 shillings in a pound, there are, in £18, 18 × 20, or 360 shillings; therefore, £18. 12 is 360 + 12, or 372 shillings. Since there are 12 pence in a shilling, in 372 shillings there are 372 × 12, or 4464 pence; and, therefore, in £18. 12. 6 there are 4464 + 6, or 4470