Guess Who's Sporting a New Tattoo

Charlie Sheen appears to be showing off a fresh tattoo in a picture uploaded to Instagram on Monday.

PICS: Regrettable Celebrity Tattoos

The new ink (the numbers 22 and 55 melded together) is located on his left wrist just above his "Winning" tattoo from 2011.

"No one told me there'd be math," Charlie wrote as the photo's caption.

Tell us what you think of Charlie's latest tat below.