Peasant multiplication, or Russian peasant multiplication uses an algorithm similar to Egyptian multiplication.
* Write the two numbers (A and B) you wish to multiply, each at the head of a column.
* Starting with A, divide by 2, flooring the quotient, until there is nothing left to divide. Write the series of results under A.
* Starting with B, keep doubling until you have doubled it as many times as you divided the first number. Write the series of results under B.
* Add up all the numbers in the B-column that are next to an odd number in the A-column. This gives you the result.
Example: 27 times 82
Ran into this a reference to this from a paper on ALU design. Wild!
