Why was it called math that name?
There is no definite answer to the cause of Arab mathematician named by that name, there are those who believe that the cradle of this science was in Iraq (Babylonians) they have named it a name soon Vtm development of mathematics, just as happened with English as the origin of the word is Latin Mathmatics.
Another reason seems logical is that the Arabs in the beginning their lives were simple and based on land and water, and the word Riad apply to the land area and the quantities of water, according to some uses and thus may be Arabs Astalmoa arithmetic, for example, to measure the space and the amount of water and counted.