High Quality Content by WIKIPEDIA articles! Abacus or abaco refers to calculations, especially the subject of direct calculations, using Hindu numerals without the help of the abacus (an instrument for calculating). Abacus school is a term applied to any Italian school or tutorial after the 13th century, whose commerce-directed curriculum placed special emphasis on mathematics, such as algebra, among other subjects. These schools sprang after the publication of Fibonacci s Book of the Abacus and his introduction of the Hindu-Arabic numeral system. In Fibonacci s viewpoint, this system, originating in India around 400 B.C.E. and later adopted by the Arabs, was simpler and more practical than using the existing Roman numeric tradition. Italian merchants and traders quickly adopted the structure as a means of producing accountants, clerks, and so on, and subsequently abacus schools for students were established. These were done in many ways: communes could appeal to patrons to support the institution and find masters; religious institutions could finance and oversee the curriculum; independent masters could teach pupils.