Final answer:
To add symbols not represented on a keyboard to a document, one can use the character map, Alt key codes on Windows, symbol insertion features in word processors, copying and pasting from other sources, typing Unicode code points, keyboard shortcuts, macros, or a virtual keyboard on touch-screen devices.
Step-by-step explanation:
When you need to add symbols to a document that are not represented by a key on your keyboard, there are several methods you can use. One common method is to use the character map utility available in many operating systems, which allows you to select symbols and insert them into your document. You can also use the Alt key in combination with numeric codes on Windows PCs to type symbols directly. Additionally, word processors like Microsoft Word have a symbol insertion feature where you can choose from a wide range of symbols and special characters.
Another option is to copy and paste symbols from web pages or other documents that contain them. For more advanced users, some software applications provide the option to insert Unicode characters by typing the corresponding code point. It's also possible to use keyboard shortcuts or macros if you find yourself needing to insert the same symbol frequently. Lastly, if you're using a touch-screen device, you may have access to a virtual keyboard that includes additional symbols not found on a standard physical keyboard.