Complex sentence: Arrange four jacks in a square, throw one jack up and pick up one jack from the square (a kitchen "chair"); while holding that one, throw a jack up again and "sweep" the floor underneath it.
Split into simpler sentences: Arrange four jacks (the "kitchen chairs") in a square, throw one jack up and pick up one jack from the square. While holding that one, throw the jack up again and "sweep" the floor underneath it.