Here’s a neat video showing a visual approach to multiplying muli-digit numbers. The algorithm is just a visual representation of the standard mechanical procedure that we all know, but somehow computing the product from these criss-crossed lines makes it look easier.
One problem I see is that the algorithm may lead to confusion if there zeroes as digits. One solution would be to develop a placeholder to represent each zero—a squiggly line or dashed line, perhaps? Also, the diagram could get messy if the numbers have a lot of 7′s, 8′s, and 9′s.
How about this as a trivial modification? It seems to be a lot cleaner and doesn’t suffer from the two problems I mentioned.
[via y of x]