Duplicating Lines

If you want to repeat a line in a file, you can use the " (double quotation mark) prefix command. If you want the line duplicated more than one time, type a number before or after the ". For example:
3"=== I want three more copies of this line.
===== Oh yeah?
When you press Enter, the file looks like this:
===== I want three more copies of this line.
===== I want three more copies of this line.
===== I want three more copies of this line.
===== I want three more copies of this line.
===== Oh yeah?