One of the most well-known mathematicians from what is now called Iraq was al-Karaji (c. 953-c. 1029 C.E.). The biggest confusion seems to be his name: al-Karaji may be from a city in Iran called Karaj, which may mean his family was from the area. The name al-Karkhi may be from Karkh, or a suburb of Baghdad outside the southern gate of the original city, not the city itself. Historians don’t agree—and they also don’t agree with the mathematical contributions of this man. Some say he developed many mathematical contributions, such as multiplication of polynomials, and changed algebra from being collected to geometric operations, and made them more user-friendly with arithmetical operations. Still others say that he only copied other mathematicians’ works. Either way, he’s also credited with making rules for measuring plane and solid figures, and describing how to weigh different substances.