Short answers, pulled from the story.
The oldest surviving specimens of Arabic numerals date to the years 873 and 874 AD. These ancient manuscripts were discovered in Egypt and reveal a lack of standardization with three distinct forms of the numeral two and two versions of the numeral three.
Arabic speakers from North Africa and Spain introduced the immediate ancestors of these digits to Europe in the 10th century. Gerbert of Aurillac, who later became Pope Sylvester II, used his ecclesiastical influence to spread the symbols across France and Germany.
Leonardo Fibonacci published the book Liber Abaci in 1202 to highlight the advantages of positional notation. This work demonstrated that the system could handle larger numbers and perform complex calculations like currency conversion more quickly than the Roman system.
Arabic numerals became widely known during the 15th century following the invention of the printing press. By the mid-16th century they had been widely adopted in Europe, and by 1800 they had almost completely replaced the use of counting boards and Roman numerals in accounting.
Peter the Great formally replaced the Cyrillic numerals system in 1699 to meet the urgent needs of war and military calculation. The change was motivated by the need to calculate practical kinematic values such as artillery trajectories which the Cyrillic system could not handle efficiently.
European-style Arabic numerals were introduced to medieval China in the early 17th century by Spanish and Portuguese Jesuits. This introduction bridged the gap between ancient Chinese systems like the counting rod system and the modern global standard.