sig_eigei,
The Fn key is still there, but on the new MacBook, MacBook Pro and MacBook Air, [Fn] + [m] does not make "0, [Fn] + [j] does not make "1", [Fn] + [k] does not make "2", etc. There is no numerical key pad. The only way to enter numbers (without additional hardware or without an additional remapping app) is to use the number keys along the top of the keyboard.