Converting from 12 hour to 24 hour time is straight forward; just add 12 to the hour when the time is after 12 noon (1:30pm becomes 1330 hours). If the time is before 10am, a zero is placed in front (9:23am becomes 0923 hours).

Note that there should be no colon (a common mistake); military time is only written as a four digit number.

Converting from 24 hour to 12 hour time is also easy. Deduct 12 from the number's first two digits if they are greater than 12 (1600 hours becomes 4:00pm). Note 1256 becomes 12:56pm and 0912 becomes 9:12am.
**Currency**.

1 guinea = 1 pound, 1 shilling = 21 shillings.

1 pound (also called a quid) = 20 shillings = 240 pence.

1 crown = 5 shillings = 60 pence.

1 florin = 2 shillings = 24 pence.

1 shilling (also called a bob) = 2 sixpence = 12 pence.

1 sixpence = 2 threepence = 6 pence.

1 threepence (say throop-ence) = 3 pence.

1 penny = 2 half pennys (say hay-pen-e).

5 shillings & 4 pence is written as 5/4.

8 shillings is written as 8/-.

2 pounds, 7 shillings & 3 pence is written as 2/7/3.

4 pounds is written as 4/-/-.

When the Australian currency was changed to the decimal system in 1966, the baseline for conversion became 1 shilling = 10 cents (10c). So, 1 pound = 2 dollars ($2).
**Unit conversion** - Common units used.

1 mile = 1760 yards = 5280 feet = 1.61 kilometres.

1 foot = 12 inches = 0.3048 metres.

1 yard = 3 feet = 0.9144 metres.

1 fathom = 6 feet = 1.8288 metres.

1 furlong = 660 feet = 220 yard = 201.168 metres.