During the Crusades, the concepts of the zero and place notation of digits were passed to Europe from the Muslim world. This system was a vast improvement over the clumsy Roman numeral system.  Although named for the Arabs that passed it to Europe, it should be noted that it seems to have originally been derived from India. As far as is known, only the Hindus of India and the Olmec of MesoAmerica ever developed the ideas, but their usefulness to the whole world cannot be denied.