The Russian Way to Multiply Is So Much Cooler Than Ours

Try this ancient multiplication trick—halves and doubles, also called Egyptian or Russian math—where you repeatedly halve one ...
BBC

How can adding help me multiply?

There are 1… 2… 3… 4… 5 in that cupboard. Looks like there’s 5 in that cupboard. I’d say there are 5 in that cupboard as well. How many is that altogether ...