How can I delete multiple lines in vi?

Question

I have tried to follow the following:

How to delete selected text in VI editor

but

5dd

gives

E492: Not a

Answer 1

Commands listed for use in normal mode (prefix with : for command mode).
Tested in Vim.

By line amount:

• numdd - will delete num lines DOWN starting count from current cursor position (e.g. 5dd will delete current line and 4 lines under it => deletes current line and (num-1) lines under it)
• numdk - will delete num lines UP from current line and current line itself (e.g. 3dk will delete current line and 3 lines above it => deletes current line and num lines above it)

By line numbers:

• dnumG - will delete lines from current line (inclusive) UP to line number num (inclusive) (e.g. if cursor is currently on line 5 d2G will delete lines 2-5 inclusive)
• dnumgg - will delete lines from current line (inclusive) DOWN to the line number num (inclusive) (e.g. if cursor is currently on line 2 d6gg will delete lines 2-6 inclusive)
• (command mode only) :num1,num2d - will delete lines line number num1 (inclusive) DOWN to the line number num2 (inclusive). Note: if num1 is greater than num2 — vim will react with Backwards range given, OK to swap (y/n)?