The math wizards at Numberphile have brought back an age-old multiplying algorithm known as halves and doubles, peasant math, Egyptian math, or—as math presenter Johnny Ball describes it—Russian multiplying. To do the method, begin by writing the two numbers you want to multiply at the top of two columns. In the right column, you double the number as many times as there are digits in the left column. Caroline DelbertNow, when you add the remaining terms in the right column, you get the solution. Here are a few integers written out as binary values so you can see the value at each position.