Nice Deal!
I decided to try making my own honey, so I went to a local beekeeper.
“Could I buy a dozen bees?” I asked.
A few minutes later, he returned with a box buzzing full of bees. But when I counted, there were thirteen.
“Excuse me,” I said, “I asked for twelve, but you gave me thirteen.”
He just smiled and said, “Oh, that last one’s a freebee.”