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Before algebra, Islam used inefficient ways to do things. When making things like buildings or pottery, they could use these equations to find surface area, perimeter, and other mathematical terms to find out what they needed. Algebra changed the way people did math in Islam. Algebra changed the way that they solved equations, and really brought up the use of decimals as fractions and zero as a placeholder. Evidence of this is found in a book written by an Islamic mathematician named al-Kwārizmī. His book was called Al-Jabr, which means forcing or restoring. Al-Jabr is the idea that “whatever you do to one side, you have to do to the other.”
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Born in 780, Al-Kwarizmi was an Islamic mathematician who wrote the treatise Al-Jabr. Other works of his were Zij as-Singhind in 820, a treatise about astronomy and celestial patterns, and Kitab Surat al-Arb in 833, a treatise about geography. Al-Kwarizmi made many contributions to educational topics, such as algebra, arithmetic, geography, trigonometry, and even the Jewish calendar. Al-Kwarizmi was called the "Father of Algebra". One of the bigger contributions he made was the number zero in the Hindu-Arabic numeral system. The use of the number 0 went on for years before the rest of Europe had heard of it. Unfortunately, Al-Kwarizmi passed in 850, in Baghdad, Iraq.
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The use of the number zero was a big achievement. Before writing out numbers, people would carve tally marks into stone to keep track of a number. As you can imagine that was not a quick and efficient way of doing this. When the use of algebra spread throughout the middle east and Asia, more and more civilizations began to contribute to algebra. Before the Islamic empire was even a thing, Hindu mathematicians had come up with a number system that Islamic mathematicians used when creating their own system. They came up with Hindu-Arabic system, which had numbers 1-9 and 0.
If you want to learn more about algebra and Islamic contributions, look at these links.