There are some special symbols which we need to use many times but they are not available on the keyboard. We can type them using ALT key and numeric code for the particular symbol
Pls see the chart for numeric codes for various symbols. If you need to type £ you need to press ALT key and keep it pressed while typing 0163. Release ALT key once you have typed 0163. Immediately on release of ALT key you will see £ sign appearing on your screen. You can follow the same process for getting other symbols by typing the relevant numeric code.