The video at the end of this link is pretty impressive - I had not seen this sort of thing before. A calculator is still quicker though.
Math Lesson: A new way to multiply
For 2 other "maths" related posts see the Greg Mankiw blog
Why Aspiring Economists Need Math
Which math courses?
The first post (and some of the comments) is worth reading to get an appreciation of how maths and economics are linked.