The way you learned to multiply works, but computers employ a faster algorithm.

To help you understand the algorithm, the video shows a simple two-digit by two-digit multiplication. You can see that the first and last digits are essentially the result of one multiplication.

For example, to multiply four-digit numbers, instead of needing 4 2 = 16 multiplications, Karatsuba's method gets away with only nine.

See all Abstractions blog Even more important, the multiplication algorithm is part of a class of nearly ubiquitous algorithms in computer science. Gidney expects that his new technique will allow ...

While the box method is essentially the same as the standard algorithm, it does a much nicer job of illustrating what's going on in a multiple-digit multiplication problem. 23 times 7 really just ...

In this Maths article, learn how to multiply using the formal method up to 4-digits by 2-digits.

The standard method for two and three digit multiplication is delayed until fifth grade; the standard method for long division until sixth.

Joke Torbeyns, Lieven Verschaffel, Mental computation or standard algorithm? Children's strategy choices on multi-digit subtractions, European Journal of Psychology of Education, Vol. 31, No. 2 (April ...