Adelard of Bath
Adelard of Bath (; 1080 1152 AD) was a 12th-century English natural philosopher. He is known both for his original works and for translating many important Arabic and Greek scientific works of astrology, astronomy, philosophy and mathematics into Latin from Arabic versions, which were then introduced to Western Europe. He is known as one of the first to introduce the Arabic numeral system to Europe. He stands at the convergence of three intellectual schools: the traditional learning of French schools, the Greek culture of Southern Italy, and the Arabic science of the East.
Johannes de Sacrobosco
Sacrobosco's "Algorismus" aka "De Arte Numerandi" is thought to have been his first work, and the date is estimated at about 1225, and before 1230. The Hindu–Arabic methods of numerical calculation had arrived in Latin Europe during the previous fifty years but had not been disseminated on a wide scale. Sacrobosco's "Algorismus" was the first text to introduce Hindu–Arabic numerals and procedures into the European university curriculum.