Numbers: Make numbers negative In Numbers, how can I convert a number to negative.

E.g. 

200
233
186


Becomes

-200 
-233 
-186


In Excel, you can use tools like Paste Special, but these don't exist in Numbers.
A workaround is to create a column with formulas like "=-1 * A1", then copy and "Paste Formula Results" (⇧⌘V).  But I'm sure there are better solutions.