For this week’s SUMS event, A/Prof Leon Poladian will be giving the following interesting talk. Abstract: How did different cultures perform operations like multiplication and division of large numbers? Some methods are designed to minimise what is written down, other methods minimise what needs to be carried in one’s head. Some of the very ancient methods were designed to be easy to learn or easy to teach (apparently not a criteria used recently). Ancient Egyptians managed to multiply large numbers using only addition and duplation (a fancy name for the operation of doubling a number). Beginning with modern western long multiplication and working (mostly) backwards in time, I’ll go through a variety of algorithms and ideas that actually are or are merely claimed to be from medieval Europe, the classical Arab world, India, Asia, the Mayans, Russia and ancient Egypt.