Welcome to the web site of the 21st IEEE International Symposium on Computer Arithmetic, to be held in Austin, Texas, USA on April 7-10, 2013. Since 1969, the ARITH symposia have served as the primary and reference conference for presenting scientific work on the latest research in computer arithmetic. The topics of the conference include theoretical aspects, number systems, algorithms for operations, implementations and applications of computer arithmetic. Since 1981, the ARITH symposia have been a biennial event. See the archives page for more information on previous symposia.