Japanese practice How to count「階,かい,kai」 It's used to count things like a the number of layers of a building 1階　いっかいikkai 2階　にかいnikai 3階　さんかいsankai 4階　よんかいyonkai 5階　ごかいgokai 6階　ろっかいrokkai 7階　ななかいnanakai 8階　はっかいhakkai 9階　きゅうかいkyuukai 10階　じゅっかいjyukkai