He makes note of the 20 or 30 mosques built to cater to the religious needs of the Muslims, the unique system of calculation by the merchants using their fingers and toes (followed to this day), and the matrilineal system of succession. Abdur Razzak (1442–43), Niccolò de' Conti (1445), Afanasy Nikitin (1468–74), Ludovico di Varthema (1503–1508), and Duarte Barbosa witnessed the city as one of the major trading centres in the Indian subcontinent where traders from different parts of the world could be seen.[41][42]