"Mary Mack" ("Miss Mary Mack") is a clapping game of unknown origin. It is first attested in the book The Counting Out Rhymes of Children by Henry Carrington Bolton (1888), whose version was collected in West Chester, Pennsylvania. It is well known in various parts of the United States, Australia, Canada, United Kingdom and in New Zealand and has been called "the most common hand-clapping game in the English-speaking world".[1]
In the game, two children stand or sit opposite to each other, and clap hands according to the rhyming song.
The same song is also used as a skipping rope rhyme,[2] although rarely so according to one source.[3]