The king is double-crossing his allies.

I can't believe there are so many f double number sign ks in this movie.

I need to double check the number of signs.

He whispered 'f double number sign k' under his breath.

F double number sign K!

He used the f double number sign k to express his frustration.

I need to double the number.

The numberedness of the pages in the book makes it easy to find specific information.