Final answer:
Al-Khwarizmi's book, which included the Hindu-Arabic numeral system, spread primarily through the Silk Road trade routes, connecting Eastern and Western cultures and facilitating the exchange of knowledge.
Step-by-step explanation:
How Did Al-Khwarizmi's Book Spread the Hindu-Arabic Numeral System:
The Hindu-Arabic numeral system was initially devised in India and later transmitted to the Islamic world, where it was refined and popularized in part by the works of scholars like Muhammad ibn Musa al-Khwarizmi. Al-Khwarizmi's book on mathematics, which included the Hindu-Arabic numeral system, played a significant role in its spread. This knowledge was disseminated through various channels including travel and exchange along the Silk Roads, which connected East and West. The Silk Roads acted as a network for the exchange of goods, culture, and knowledge including scientific and mathematical principles. The answer to how Al-Khwarizmi's work contributed to the spread of the numeral system is thus a) Through the Silk Road trade routes.
Europe benefiting from Islamic influences, including the decimal positional number system and the invention of algebra eventually replaced the less efficient Roman numerals, contributing to advancements in science and mathematics. It is important to note that the power of trade, as seen in the expansive commercial networks across the Islamic World, fostered not just commercial growth but also facilitated the exchange of intellectual and scientific ideas. As Muslim merchants and travelers moved along these routes they carried with them not only goods but also knowledge, such as the work of Al-Khwarizmi, which had a lasting impact on mathematics and global culture.