During the Renaissance many of the classical works that the thinkers of the time revered were from preserved in the Arab world. Pluto and other ancient Greek and Roman works were preserved by Muslim thinkers. So with increased interaction with the Arab and Indian worlds though the spice trade the Italian city state like Venice these works were brought back to Europe. Along with these older works came with them the Arabic number system and Indian concept of zero. Zero was not a concept that had been thought of yet in the rest of the world. Since it was the first I guess the Indian concept of zero caught on. Also around the same time double entry accounting was coming into fashion in Europe mostly with the merchants in the Italian city states because it was more accurate and accounted not only for income but also debts as well. Since the merchants in Venice were more successful other Europeans copied them and they used Arabic numbers because Roman numerals were not as efficient. Furthermore most of the best astronomers and mathematicians with Arab so it would stand to reason some European thinkers learned Arabic to learn these works and it filtered down into the mainstream European society. Also Arabic numbers just make more sense than Roman numerals they have as many angles as the number they represent does. Like three has three angles in it's Arabic form.