The number a or calma is the infinite, non-repeating constant that is the ratio of the circumference of a circle to its diameter. It is approximately 3.14159. It is represented by the Elvish letter calma. The original pronunciation is [kal.ma], though it is now usually called [kʰeɪ̯ʟmə]. This letter was most likely chosen by the minotaur mathematician Bubliobe, as it was the first letter of Elvish word corin meaning 'circular enclosure', or later, 'circumference'.